Xenomorph

The Xenomorphs or, the Aliens, are a race of extremely vicious and deadly insect-like humanoid parasites featured in the Alien and Alien vs. Predator franchises. The species made its debut in the film Alien (1979) and reappeared in the sequels Aliens, Alien 3, and Alien Resurrection, as well as the prequels Prometheus and Alien: Covenant and crossover films Alien vs. Predator and Aliens vs. Predator: Requiem. The Alien from Alien (1979).]]. The creatures originate from Xenomorph Prime.

Concept and creation
The script for the 1979 film Alien was initially drafted by Dan O'Bannon and Ronald Shusett. Dan O'Bannon drafted an opening in which the crew of a mining ship are sent to investigate a mysterious message on an alien planet. He eventually settled on the threat being an alien creature; however, he could not conceive of an interesting way for it to get onto the ship. Inspired after waking from a dream, Shusett said, "I have an idea: the monster screws one of them", planting its egg in his body, and then bursting out of his chest. Both realized the idea had never been done before, and it subsequently became the core of the film. "This is a movie about alien interspecies rape," O'Bannon said in the documentary Alien Evolution. "That's scary because it hits all of our buttons." O'Bannon felt that the symbolism of "homosexual oral rape" was an effective means of discomforting male viewers.

The title of the film was decided late in the script's development. O'Bannon had quickly dropped the film's original title, Star Beast, but could not think of a name to replace it. "I was running through titles, and they all stank", O'Bannon said in an interview, "when suddenly, that word alien just came out of the typewriter at me. Alien. It's a noun and it's an adjective." The word alien subsequently became the title of the film and, by extension, the name of the creature itself.

Prior to writing the script to Alien, O'Bannon had been working in France for Chilean cult director Alejandro Jodorowsky's planned adaptation of Frank Herbert's classic science-fiction novel Dune. Also hired for the project was Swiss surrealist artist H. R. Giger. Giger showed O'Bannon his nightmarish, monochromatic artwork, which left O'Bannon deeply disturbed. "I had never seen anything that was quite as horrible and at the same time as beautiful as his work" he remembered later. The Dune film collapsed, but O'Bannon would remember Giger when Alien was greenlit, and suggested to director Ridley Scott that he be brought on to design the Alien, saying that if he were to design a monster, it would be truly original.

After O'Bannon handed him a copy of Giger's book Necronomicon, Scott immediately saw the potential for Giger's designs, and chose Necronom IV, a print Giger completed in 1976, as the basis for the Alien's design, citing its beauty and strong sexual overtones. That the creature could just as easily have been male or female was also a strong factor in the decision to use it. "It could just as easily fuck you before it killed you," said line producer Ivor Powell, "[which] made it all the more disconcerting." Fox Studios were initially wary of allowing Giger onto the project, saying that his works would be too disturbing for audiences, but eventually relented. Giger initially offered to completely design the Alien from scratch, but Scott mandated that he base his work on Necronom IV, saying that to start over from the beginning would be too time-consuming. Giger signed on to design the adult, egg and Chestburster forms, but ultimately also designed the alien planetoid LV-426 and the Space Jockey alien vessel.

Giger conceived the Alien as being vaguely human but a human in full armor, protected from all outside forces. He mandated that the creature have no eyes, because he felt that it made them much more frightening if you could not tell they were looking at you. Giger also gave the Alien's mouth a second inner set of pharyngeal jaws located at the tip of a long, tongue-like proboscis which could extend rapidly for use as a weapon. His design for the creature was heavily influenced by an aesthetic he had created and termed biomechanical, a fusion of the organic and the mechanic. His mock-up of the Alien was created using parts from an old Rolls Royce car, rib bones and the vertebrae from a snake, molded with plasticine. The Alien's animatronic head, which contained 900 moving parts, was designed and constructed by special effects designer Carlo Rambaldi. Giger and Rambaldi together would win the 1980 Academy Award for Visual Effects for their design of the Alien.

Scott decided on the man-in-suit approach for creating the creature onscreen. Initially circus performers were tried, then multiple actors together in the same costume, but neither proved scary. Deciding that the creature would be scarier the closer it appeared to a human, Scott decided that a single, very tall, very thin man be used. Scott was inspired by a photograph of Leni Riefenstahl standing next to a 6'4" (1.93 m) Nuba man. The casting director found 6'10" (2.08 m), rail-thin graphic designer Bolaji Badejo in a local pub. Badejo went to tai chi and mime classes to learn how to slow down his movements.

Giger's design for the Alien evoked many contradictory sexual images. As critic Ximena Gallardo notes, the creature's combination of sexually evocative physical and behavioral characteristics creates "a nightmare vision of sex and death. It subdues and opens the male body to make it pregnant, and then explodes it in birth. In its adult form, the alien strikes its victims with a rigid phallic tongue that breaks through skin and bone. More than a phallus, however, the retractable tongue has its own set of snapping, metallic teeth that connects it to the castrating vagina dentata."

Name
This creature has no specific name; it was called an alien and an organism in the first film. It has also been referred to as a creature, a serpent, a beast, a dragon, a monster, a nasty, or simply, a thing. The term Xenomorph (lit. "alien form"—from Greek xeno-, which translates as either "other" or "strange", and -morph, which denotes shape) was first used by the character Lieutenant Gorman in Aliens with reference to generic extraterrestrial life. The term was erroneously assumed by some fans to refer specifically to this creature, and the word was used by the producers of some merchandise. The species' binomial names are given in Latin as either Internecivus raptus (meant as "murderous thief") or Lingua foeda acheronsis (meant as "foul tongue from Acheron"). The main Alien from Alien vs. Predator is listed in the credits as "Grid", after a grid-like wound received during the film from a Predator's razor net. Alien: Covenant actually credits the Alien as Xenomorph, while also listing a different variety of the creature as the Neomorph. In The Weyland-Yutani Report, the Alien encountered by the Nostromo was specifically referred to as "Xenomorph XX121".

Alien (1979)
Main article: Alien

On its way back to Earth, the U.S. commercial spaceship USCSS Nostromo is diverted to a desolate planetoid by a cryptic signal from a derelict alien spacecraft. While exploring the alien ship, one of the Nostromo 's crewmen discovers the remains of the ship's pilot and also a large chamber that contains thousands of egg-like objects. One of the eggs releases a creature that attaches itself to his face and renders him unconscious. The others break quarantine to bring him back aboard the ship. The parasite dies and the crewman wakes up, seemingly fine. Soon afterwards, an alien organism bursts from his chest and grows extremely rapidly into a terrifying eight-foot (about 2.5 meters) tall creature that starts killing off the crew.

Aliens (1986)
Main article: Aliens

After 57 years in hypersleep, the sole survivor of the USCSS Nostromo, WO Ellen Ripley, awakens aboard a medical space station orbiting Earth. Her story of the Alien terror she encountered is disbelieved and she learns that the planetoid from the first film (now designated as LV-426 or Acheron) is now home to a terraforming colony. When contact with the colony is lost, Ripley, against her better judgment and to regain her pilot's license, hesitantly accompanies a squad of high-tech Elite Colonial Marines aboard the spaceship Sulaco to investigate. Once there, they discover the colonists have been wiped out after finding the derelict alien ship (and its deadly cargo) from the first film.

Alien³ (1992)
Main article: Alien³

Due to a fire aboard the USS Sulaco, an escape pod carrying the survivors of the second film is automatically jettisoned. It crash-lands on the refinery/prison planet Fiorina "Fury" 161, but Ripley is the only one to survive the crash. Unbeknownst to her, an Alien Facehugger was also aboard the ship. Before long, a full-sized Alien is then loose in the prison, killing the inmates and staff. Ripley also discovers there is an Alien queen growing inside her, and must not only kill the rampaging Alien but also herself in order to save humanity.

Alien Resurrection (1997)
Main article: Alien Resurrection

Two hundred years after the events of the previous film, several clones of Ellen Ripley (including the alien queen she was carrying) are produced. The Alien queen is surgically removed from her body as the United Systems Military hopes to breed Aliens to study on the spaceship USM Auriga, using human hosts kidnapped and delivered to them by a group of mercenaries onboard a transport starship called the Betty. The Aliens escape their enclosures, while Ripley 8 (a clone mixed with Alien DNA) and the mercenaries attempt to escape and destroy the Auriga before it reaches Earth.

Alien vs. Predator (2004)
Main article: Alien vs. Predator

In 2004, a Predator ship arrives in Earth orbit to draw humans to an ancient Predator training ground on Bouvetøya, an island about one thousand miles north of Antarctica. A buried pyramid which gives off a "heat bloom" attracts humans led by Charles Bishop Weyland (Lance Henriksen), who unknowingly activates an Alien egg production line. Three Predator hunter initiates (also called "youngbloods") enter the structure, killing all humans in their way with the intention of hunting the newly formed alien warriors. Two Predators die in the ensuing battle, while the third allies itself with the lone surviving human, Alexa Woods (Sanaa Lathan) in order to battle the escaped Queen Alien. The Queen is defeated, but not before she fatally wounds the last Predator. The Predator ship hovering above the battleground uncloaks and the crew retrieve the fallen Predator. A Predator elder gives Alexa a spear as a sign of respect, and then departs. Once in orbit it is revealed that a chestburster was in the corpse, though this specimen has Predator mandibles.

Aliens vs. Predator: Requiem (2007)
Main article: Aliens vs. Predator: Requiem

Set immediately after the previous film, the Predalien hybrid on board the Predator scout ship, which just separated from the mothership from the previous film, has grown to full adult size and sets about killing the Predators on board the ship, causing it to crash in Gunnison, Colorado. The last survivor activates a distress beacon with a video of the Predalien, which is received by a veteran Predator, who sets off towards Earth to "clean up" the infestation. When it arrives, the Predator tracks the Aliens into a section of the sewer below town. He removes evidence of their presence as he goes by using a corrosive blue liquid. It uses a laser net to try to contain the creatures, but the Aliens still manage to escape into the town above. The Predator fashions a plasma pistol from its remaining plasma caster and hunts Aliens all across town (accidentally cutting the power to the town in the process). During a confrontation with human survivors, the Predator loses its plasma pistol. The Predator then fights the Predalien single-handedly, and the two mortally wound one another just as the US military drops a tactical nuclear bomb on the town, incinerating both combatants as well as the few remaining humans in the city. The salvaged plasma pistol is then taken by the United States Army to Ms. Yutani.

Prometheus (2012)
Main article: Prometheus

Some thirty years before the events of Alien, scientists Elizabeth Shaw and Charlie Holloway discover a star map among the remnants of several ancient Earth cultures. Seeking the origins of humanity, they journey aboard the spaceship Prometheus and arrive on the distant planet LV-223 in the Zeta Reticuli system, the same region of space in which the planetoid LV-426 from Alien is found. There they discover the remains of an advanced civilization (the same race as the dead pilot from the derelict ship in Alien), who were developing biological weapons which could have driven the human race extinct.

Alien: Covenant (2017)
Main article: Alien: Covenant

Eleven years after the events of Prometheus, the colony ship USCSS Covenant, carrying thousands of colonists and hundreds of human embryos in cryo-stasis, makes its way towards the planet Origae-6. The crew intercepts a transmission sent from Shaw, which they decide to trace to an apparently habitable Engineer home world (referred to as Planet 4), devoid of all non-floral life. When several crew members are infected by the mutagen and give birth to a new breed of Alien, the Neomorphs, the android David 8 rescues them. His motivations to produce Aliens and destroy human life are made apparent, however, and with the birth of yet another new breed of Alien the survivors, now led by Daniels, are forced to flee from the world. After disposing of the Alien chasing them, the crew members return to the Covenant and are put back into cryosleep by someone they believe to be their shipboard synthetic, Walter. Only when Daniels is put in her cryopod does she realize that Walter has been replaced by the identical David. With the crew, colonists and embryos at his mercy, David contacts Weyland-Yutani back on Earth, stating that while the majority of the crew was killed in the neutrino blast, they would be continuing on towards Origae-6.

Biography
The Xenomorphs are vicious predatory creatures with no higher goals than the propagation of their species and the destruction of any life that could pose a threat to them. Like wasps, ants or bees, Xenomorphs are eusocial, with a fertile Queen breeding a host of subordinate castes. The creatures are known for their potent acid blood, tails and their inner jaws, although their biological life cycle, in which their offspring are implanted inside living hosts before erupting violently from their chests, is in many ways their signature aspect. Xenomorphs are primarily solitary ambush hunters, although they have been known to adopt swarm tactics when acting in larger groups. Despite their voracious ability to kill, they often seek to take their victims alive to be hosts for more Xenomorphs; victims are taken to the hive (or simply a secluded location if no hive exists), cocooned and/or immobilized before being impregnated with a Xenomorph embryo. However, when their target becomes a threat or is deemed unsuitable for harvest, the Xenomorph will not hesitate to quickly dispatch the chosen host.

Notably, Xenomorphs will alter their physical appearance during development depending on the physiology of the host in which they gestate — in all likelihood, this incorporation of physical traits gleaned from the host is designed to ensure the adult creature is better suited to the environment in which it will find itself. This ability to alter its form based on the host's physical attributes occurs at a cellular level and has been referred to as the "DNA Reflex". Historically, most Xenomorphs encountered have typically gestated inside human hosts, and therefore adopt a basically bipedal, humanoid stance, but other variations born from a wide variety of different host organisms have been seen, and as a result feature varying physical appearances. However, regardless of any physical variation resulting from the host, Xenomorphs always possess certain distinctive, trademark characteristics.

Outwardly, they have a skeletal, biomechanical appearance and are usually coloured in muted shades of black, blue or bronze. Whatever the host organism, they invariably possess distinctive, elongated, cylindrical skulls, but possess no visible facial features other than their mouth. The carapace atop the head has been seen to vary, from smooth and vaguely translucent to ridged and opaque. It has been proposed that this difference is part of a maturation process, and that younger creatures or Drones possess the smoother, domed carapace, while older specimens, such as Warriors feature ridges. Notably, ridges are often visible beneath the smooth dome of Drones.

The Xenomorphs' main weapon is their inner pharyngeal jaw, which is capable of shooting out from their mouth like a tongue with enough power to smash through bone and metal. In fact, a common tactic used by the creatures to eliminate prey is to restrain the victim with their hands, immobilizing them, before killing them with a precision jaw strike to the forehead, piercing through the skull and penetrating to the brain. This form of attack is known as a "Headbite". On several occasions, Xenomorphs have been seen to suspend the corpses of those that they kill from ceilings.

Xenomorphs also have extended, bladed tails. The sharp tip has been seen to vary from a small, scorpion-like blade. Despite their seemingly flimsy physical construction, the creature's tail makes for an incredibly potent weapon, strong enough to stab and lift a human with seemingly little effort. The tails have been used variously as stabbing, whipping, slashing and used as weapons. Above the tails, the creature possesses several tube-like spikes on its back, typically consisting of two pairs — a larger upper pair and a smaller lower pair — often with a fifth, sharper spine in the centre below the base of the head. The exact purpose of these tubes is unclear.

As a result of the DNA Reflex, Xenomorphs have appeared as both plantigrade and digitigrade organisms, usually in accordance with their host. For example, Xenomorphs typically possess humanoid hind limbs and walk upright, while Xenomorphs spawned from animal hosts (referred to as "Runners") sport double-jointed hind legs and move on all fours. The Cloned Xenomorphs created aboard the USM Auriga also possessed digitigrade legs despite spawning from human hosts, perhaps as a result of imperfections and cross-contamination in the cloning process.

When standing upright, Xenomorphs are vaguely bipedal, though they can be in a quadrupedal manner when walking or moving on all four limbs in an even in instances where the host was a bipedal lifeform, such as humans. They are quite capable of running and crawling along ceilings and walls. They are also expert climbers and jumpers. They are extremely strong as they possess super strength, having been known to break through metal vent covers and welded steel doors with little effort, and even of breaking down reinforced pressurized doors over time. Their taloned claws are more capable of scratching, ripping or tearing prey apart, while their primary jaws are capable of producing a bite strength estimated at 6,000 psi.

Xenomorphs do not radiate heat, and their body heat matches the ambient temperature of the environment in which they are found. Adverse extremes of temperature appear to have little, if any, affect on their physical prowess. In fact, physiologically they are incredibly hardy creatures and aside from being unaffected by temperature extremes that would quickly incapacitate or kill a human, they are capable of surviving in space, at least for a limited period of time. In order to succeed in their attack on enemy human vessels, the rage equipped attacking Xenomorphs with breathing apparatus, suggesting that the creatures do require some from of atmosphere to survive for extended periods in space. A Runner on Fiorina 161 was even known to survive several tons of molten lead being poured onto it.

Protomorph
Protomorphs are a different species of the Xenomorph race. They possess notable differences that set it apart from its mainstream cousins. Notably, it lacks any biomechanical features and its limbs are longer, thinner and skinless, with exposed muscles and blood vessels, with gaps appearing in its armpits. The shoulders and spikes are noticeably different, being smaller and narrower. The Protomorph also has a thinner, sleeker tail that ends with a small barb or stinger.

The differences in the creature extend to its Chestburster form as well as the Facehugger to a lesser extent. Other than these differences, the Protomorph greatly resembles the Xenomorphs that had come from LV-426.

Like the original Xenomorph, the Protomorph possesses an inner pharyngeal jaw. This appendage is capable of shooting from their mouth with sufficient power to smash through bone and metal. In fact, a known common tactic used by its cousins to eliminate prey is to restrain the victim with their hands, immobilizing them, before killing them with a precision jaw strike to the head, piercing through the skull and penetrating the brain. This form of attack is colloquially known as a "Headbite".

The most unique aspects about the variant is its incredible resilience and determination. The Protomorph possesses more or less the same basic intelligence but seems to be unable to differentiate between living or inorganic objects when they are moving.

Like all members of the Xenomorph species, the Protomorphs have a complex and parasitical life-cycle that requires a host. The process itself is actually completely identical with the creature having its beginnings in an Egg of similar shape to its cousins, though with notable differences in shape.

Once the egg opens, a Facehugger will emerge, attach itself to the face of a host, and immediately implant an embryo, with seemingly even a brief moment of contact being able to ensure impregnation. Though the removal of the Facehugger is less difficult compared to the mainstream variant, as it has less potent acid blood, the Planet 4 Facehugger is able to counteract these setbacks by seemingly being able implant a host within seconds of attachment.

The Protomorph Chestburster uses its shape to burst its way out of its host, and once it emerges, it undergoes almost immediate transformation. Due to this species accelerated growth, the Protomorph Chestburster itself seems to be born almost fully developed, similar to a Chestburster that emerged from an animal on Fiorina Fury 161.

Known Xenomorphs
Nostromo Xenomorph: The Nostromo Xenomorph or referred as the Alien was a lone Xenomorph Drone spawned from Kane on board the Nostromo after he was impregnated by a Facehugger inside a derelict Engineer spaceship. The creature was responsible for killing all but one of the Nostromo's crew in just a few hours. It was eventually killed by Ripley, who ejected it into space and incinerated it with the engines after she failed to destroy it when she set the Nostromo to self-destruct and escaped in the ship's shuttle.

Acheron Queen: The Acheron Queen was a Xenomorph Queen that was born on Acheron (LV-426). She was the leader of her hive at the colony of Hadley's Hope and was later encountered by a unit of Colonial Marines from the USS Sulaco. The Queen escaped her hive after Ripley incinerated her collection of eggs, causing the enraged Queen to give chase and fled the colony before it was destroyed. She managed to reach the Sulaco by stowing away on board a dropship, but she was defeated by Ripley, who flushed her into space to her death.

The Dragon: The Dragon was a lone Xenomorph Runner spawned from Spike on Fiorina "Fury" 161 after the dog was impregnated by a Facehugger that was hidden on board the Sulaco's EEV that brought Ripley to the planet. The creature was responsible for killing nearly all of the inhabitants of the Fiorina 161 Class C Work Correctional Unit. It was eventually killed by Ripley, who covered it in molten lead and drenched it in water from the fire sprinklers, causing the Runner to explode.

Cloned Queen: The Cloned Queen was a Xenomorph Queen clone that was born on board the Auriga. She was the leader of the Cloned Xenomorphs that were bred by the United Systems Military on board the vessel. She later replaced her Egg sac with a womb and gave birth to the "Newborn", a human/Xenomorph hybrid as a result of genetic crossing with her host Ripley 8, a clone of Ripley. The Queen was killed by the Newborn after it viewed Ripley 8 as its true "mother" instead of the Queen.

Newborn: The "Newborn" was a mutated human/Xenomorph hybrid spawned from the Cloned Queen's womb on board the Auriga. The creature emerged as a product of cloning experiments conducted by scientists of the United Systems Military, created when the Cloned Queen produced as a result of the experiments became contaminated with human DNA, granting her a second reproductive cycle using a womb and a live birth. Instead of the Queen that gave birth to it, the Newborn killed her and it had Ripley 8, a clone of Ripley that had originally been host to the Queen, as its true "mother" instead. It was killed by Ripley 8 after she spilled her acid blood on a window and made a little hole in the hull of the Betty, causing the Newborn to be sucked violently through it and blowing its remains into outer space.

Grid: Grid was a Xenomorph Drone that acted as the alpha of the Xenomorphs and was born in an ancient pyramid beneath Bouvet Island. Its name was given due to net wounds when getting constricted in Celtic's net. Grid was responsible for killing two Young Blood Predators Chopper and Celtic, who had come to the pyramid to hunt Xenomorphs as part of an initiation hunt, and later freed the Antarctic Queen held captive by Predators deep within the pyramid. Grid was ultimately killed when Scar destroyed the entire pyramid with his self-destruct device.

Antarctic Queen: The Antarctic Queen was a Xenomorph Queen captured by Predators inside an ancient pyramid beneath Bouvet Island and used to breed Xenomorphs that would later be hunted by Predators in initiation rituals. During one hunt, the Queen escaped from her restraints and fled the pyramid after it was destroyed by Scar's self-destruct device, but was fought and defeated by him with the help of Lex Woods. The Queen apparently drowned when she was thrown into an ocean and was dragged underwater to her watery grave by a huge water tower that she was chained onto.

Gunnison Predalien: The Gunnison Predalien was a Predalien spawned from Scar after the Predator was impregnated by a Facehugger during his hunt in an ancient pyramid beneath Bouvet Island. The creature was responsible for terrorizing the town of Gunnison on Earth by impregnating hosts and producing an army of Xenomorphs. It was eventually killed when a tactical nuclear bomb was dropped on the town while fighting Wolf, a veteran Predator who arrived on Earth to kill it and both are incinerated in the explosion along with the Xenomorphs and the town's residents.

Senses & Acid Blood
Xenomorphs possess several senses. First and foremost, the creatures have sensory structures along the sides of their extended skulls that are capable of perceiving atmospheric vibrations (sound). Given the lengthy structure of the head, which gives the creature a wide field of "hearing", this is thought to be the Xenomorph's primary means of rationalizing its environment. The creatures are also capable of detecting heat via highly sensitive thermore active organs located behind the skull's frontal plate — which is itself constructed of the unusual C60 carbon-lattice, known to demonstrate exceptional conducive properties. Finally, the creatures possess largely vestigial photosensitive organs flanking the frontal plate; these visual receptors are thought to aid the creatures in seeing each other (Xenomorphs produce no notable body heat, a fact that would otherwise render them blind to their thermal receptors). These remnant visual organs are also thought to grant the creature the necessary depth perception required when attacking prey.

Xenomorph blood is an extremely potent and concentrated molecular acid that can corrode on contact almost any substance with alarming speed. It is dull yellowish-green colour. The blood is in fact a component in a biological "battery" that provides the creatures with their energy, and seems to be pressurized inside the body so that it spurts out when wounded, as a defensive measure. This blood can prove incredibly problematic when encountering Xenomorphs aboard a starship, as using traditional firearms or explosives to attack the creature will potentially cause its blood to leak out in sufficient quantity to eat through the hull of the ship. In some instances, Xenomorphs have been known to be conscious of the effects of their acid blood, and even exploit it to their advantage. Some of the Xenomorph such as Runners have been known to "spit" acid, either as a tool or a form of attack. For example, Facehuggers have been known to regurgitate a small amount of acid to melt through obstructions between them and a potential host, such as the faceplate of a spacesuit helmet. This spitting ability has also been exhibited offensively by adult Xenomorphs, the creatures will spit acid to blind and incapacitate their victims rather than kill them outright. Despite their own immunity to their blood, Xenomorphs are vulnerable to hydrofluoric acid, which was used against them to great effect.

Hive
The Hive is the nesting grounds of the Xenomorphs and the Queen, constructed from webbing, a gelatinous resin secreted by Drones. It is where the Queen will reside while she is laying her eggs, a state that renders her immobile, and is where those eggs are subsequently stored. Potential hosts captured by other Xenomorphs are brought to the Hive and cocooned to the walls as being "hived"  — to be implanted with Chestbursters.

Hives are built from a clear, gelatinous liquid that Xenomorphs from their mouths and eventually hardens to form a dark, strong, resinous substance, known as "webbing". This webbing is used to construct a warren-like maze of tunnels spreading outwards from a central egg chamber, where the Queen will reside. It should be noted that while a Queen is typically found overseeing a Hive, one is not necessarily required for a Hive to form. Indeed, construction of a Hive may be a precursor to Queen development in many cases. In this respect, a Xenomorph Hive shares similarities in its architecture with spider webs, while being directly comparable to neither.

The primary purpose of the webbing is twofold while it provides a surface to which potential hosts can be cocooned for implantation and birth, its non-uniform, bio-organic appearance also allows Xenomorphs to camouflage themselves when at rest, to the extent that humans have stood directly beside hiding Warriors and had no idea of the imminent threat. In the case of Hives set up inside existing non-Xenomorph structures, webbing helps to disguise existing visual cues in the environment, turning the area into a disorientating maze and making escape from and/or assaults on the Hive all the more difficult. However, whether this is considered by the Xenomorphs during construction is unclear. The structure of a Hive also appears to have a disrupting effect on motion tracker operation, generating a host of false readings that imply the entire area is awash with sporadic movement, making genuine readings harder to spot. The exact cause of this is unclear.

The atmosphere within a Hive is typically very warm. A Queen will often locate her Hive in an area where these properties are already apparent, such as large industrial facilities where there is an abundance of ambient heat. It is also possible the Hive structure, or perhaps the resident Xenomorphs themselves, somehow raise atmospheric temperatures within the Hive to meet this requirement.

Hives can vary in size from extensive nests with hundreds of members headed by an egg-laying Queen to small chambers occupied by only a few Drones or Warriors. Occasionally, in larger infestations, smaller "satellite" Hives will be set up in the areas surrounding the main nest. While these subsidiary Hives are occasionally used for the cocooning and impregnating of hosts, more often they are simply an outlying base of operations for Xenomorph Warriors. Even individual Xenomorphs operating in isolation have been known to establish small nests, although this is thought to be rare as a solitary creature has little need for a Hive of its own. The largest known Hive ever discovered is that on Xenomorph Prime, which covers half a continent.

Intelligence, Communication & Behaviour
The species excels at observational learning and problem solving. In both cases, Xenomorphs managed to learn how to operate the machinery of their mechanized environments at a very basic level. On Acheron, the Xenomorphs were able to cut the power to a section of the complex to allow themselves access to their human prey, while the Queen was able to learn how to operate an elevator simply by observing it once. It has even been suggested that the Queen may have established her "nest" at the colony's main Atmosphere Processing Plant due to some understanding that such a sensitive location would afford her a degree of protection — any attackers would be unable to destroy her and her hive without also destroying the entire facility. However, others have suggested her choice of location may simply have been the result of her selecting the warmest part of the base in which to make her nest. On the USM Auriga, captive Xenomorphs were able to use blood from one of their own kind to melt through their enclosure and escape. The Xenomorphs in the pyramid beneath Bouvet Island used a similar strategy to free their Queen from her restraints.

It has been theorized that the intelligence of individual Xenomorphs may be influenced by the host. At the very least, the creatures can apparently inherit some degree of basic instinctual urges from their host. With the distinct exception of the Newborn aboard the USM Auriga, Xenomorphs have demonstrated little actual emotion, save for basic self-preservation and maternal instincts toward their Eggs and the Queen.

The means by which Xenomorphs communicate amongst themselves is unclear, although it is apparent from their behavior that they possess the ability to do so. While Xenomorphs are able to speak a selection of hisses, screeches, growls, snarls, howls or roars, it seems probable that the majority of their communication is performed through some other means, possibly involving the use of pheromone release, ultrasound or even some form of telepathy. The creatures possess a unique ability to inherit memories genetically, passed down from one generation to another. These memories go far beyond mere base instinct, and can include recollections of very specific events witnessed by earlier generations. The purpose of this genetic memory ability is to ensure the species remains intact regardless of "the differing characteristics they might have to adopt from their varied hosts".

It has been proposed that pheromone detection and the scent of their prey's fear when confronted may determine the behavior and hostility of Xenomorphs during their attacks. Documented study appears to indicate that Xenomorphs may perform excruciating, bloody kills when sensing that their victim is terrified by their presence, while cleaner, faster kills take place when the prey either does not notice the Xenomorph or is less aware of its presence. It also seems that pheromone detection may help Xenomorphs to locate their prey, and that, since synthetics do not possess such chemicals, the Xenomorphs usually tend to ignore them as long as they are not disturbed.

They make few vocalizations beyond snarls and high pitched screeching when in pain or attacking. They regularly hiss while active, but are otherwise silent, particularly when stalking prey.

The Xenomorphs also have an enormously complex neurological structure in the dorsal region of their head. It suspected this is what Xenomorphs have instead of a brain.

Diet, Sex & Society
Little is known regarding the Xenomorph's diet. The fact that their blood generates the energy they use to power their bodies means they may not require traditional sustenance at all. Events at Hadley's Hope on Acheron seem to imply the Xenomorphs do not use the humans they capture as a food source, as Colonial Marines who entered the hive there found it to be littered with the corpses of colonists used as hosts, none of whom showed any sign of having been consumed, in whole or in part, despite the fact they had been cocooned for some time. Similarly, Marines from the USS Sephora found evidence that even bodies left cocooned for as long as 17 weeks were not desecrated or devoured in any way following death.

Further contradictory evidence demonstrates the precise opposite: for one, the Runner on Fiorina 161 was apparently seen to eat at least some of the humans that it killed. In Gunnison, Warriors were seen to feed on their victims. Hosts were known to be used as a source of food for the hive once the embryos inside them had been born, and Xenomorphs were also occasionally seen to feed on humans they had attacked, sometimes while they were still alive.

It is possible that the Xenomorphs blood generates enough energy to support the creature in a state of low or moderate activity, but that food helps it replenish energy after it has been expended after a fight, chase, or any other demanding activity, thus providing an explanation for both occurrences. Xenomorphs operate under a caste system, with groups of specialized individuals performing distinct tasks within the species. It is not clear to what degree these castes are subject to a social hierarchy, although certain Xenomorph types, notably the Queens, clearly exercise some degree of control and superiority over other more common variations.

While individual Xenomorphs have been known to operate independently, owing to their tendency to reproduce rapidly and in large numbers they are more commonly encountered in groups and often likened to an infestation owing to their tendency to spread and consume all suitable host organisms in an area. As with many other eusocial organisms, Xenomorphs, particularly in larger groups, will create a central nest or hive in which they will reside, often overseen by an egg-laying Queen. Raiding parties will be sent out into the surrounding area to search for and capture more hosts, which will then be brought to the hive and used to create more Xenomorphs. In larger infestations, smaller "satellite" hives may be created, containing just a few Xenomorphs, allowing victims to be cocooned and impregnated even far away from the Queen herself.

The question of the Xenomorph's biological sex is heavily debated. However, the preeminent theory is that the species is hermaphroditic, although even this definition is somewhat speculative as it remains unclear if individual Xenomorphs possess any sexual organs in the traditional sense. Despite this, Queens are often referred to as female, although the strict accuracy of this definition is uncertain and it is often simply a matter of convenience. Certain Yautja have been known to refer to the species collectively as all-female, although it is possible this is simply out of convenience or due to linguistic limitations.

Origins
While the exact origins of the Xenomorphs have never been definitively determined, there have been several conflicting accounts of their origins and several notable theories on their beginnings have gained widespread recognition. The creature being artificially created by using Chemical A0-3959X.91 – 15 is the most probable cause of their origin.

Perhaps the most prominent of these is that they are not a natural creature, but were created artificially to act as a biological weapon of war by another, technologically advanced race. Evidence suggested to support this includes the Xenomorph's general biomechanical biology and appearance, as well as the perceived "perfection" of their physical nature. Various individuals have proposed that the Engineers may be the race that created the Xenomorph, especially given their known propensity for advanced bio-weapons (including Chemical A0-3959X.91 – 15), although another (less widely-accepted) theory is that the Yautja may have been responsible, owing to their close and lengthy association with the creatures.

Following the android David unleashing the Chemical A0-3959X.91 – 15 mutagen on the Engineer homeworld, the local fauna and fungi were affected and led to the formation of certain fungus-like growths that upon being disturbed released tiny, insect-like spores that infected any and all animal life, leading to the gestation of Neomorphs. Converting an Engineer temple into a laboratory, David began conducting experiments studying the mutagenic properties of Chemical A0-3959X.91 – 15 on the indigenous life of Planet 4 and tissue samples taken from deceased Engineers and Neomorphs. Over the course of a decade, David was able to hybridize various strains of Neomorph with mutated eggs to create Ovomorphs carrying Facehuggers that produced a non-biomechanical strain of the Xenomorph. David infiltrated a colony ship intending to continue his experiments using the crew and colonists, with the desired end result being the creation of a Queen. Whether the biomechanical Xenomorph was created by David as a direct result of further experimentation or "naturally" evolved from, or even if they existed in some form prior to David's experiments, is unknown.

Some sources in the expanded universe dictate that the Xenomorph is as natural as any other creature, fitting into an ecosystem where it has creatures that prey on it, thus keep its population in check. Its hard carapace is the result of a harsh and unforgiving world as are its violent ways, which are described as "brutally practical". Its world, from the moment it is born to the moment it dies, is violence and death, either giving or getting. When removed from this system, however, is when they become truly dangerous as nothing keeps their numbers in check.

Human Study
Due to its unique biological makeup and perceived perfection, the Xenomorph has long been the target of extensive and at times ruthless human research. Notable leaders in this field include the Weyland-Yutani Corporation, the Grant Corporation, Lasalle Bionational and the Z.C.T. Corporation. The goals of this research range from simple understanding to the development of new alloys and vaccines to fully-fledged weaponization of the creatures and/or their biology. Owing to the Xenomorph's extreme aggression, intelligence and lethality, attempts at human study have often resulted in catastrophic containment failures and extreme loss of life. On a more practical level, creatures' potent acid blood renders dissection problematic. However, researchers have developed reliable methods for carrying out such procedures — after stunning the creatures with ultrasound, they are suspended in a saturated solution of powerful neutralizing agents that counteract the creature's acid blood. Dissection can then be carried out using remote sensor arms with tight-beam xenon-focused cutting lasers.

Despite the inherent dangers involved in studying them, organizations remain committed in their attempts to unravel the creature's mysterious and complex biology and bend it to humanity's requirements.

Chemical A0-3959X.91 – 15
Chemical A0-3959X.91 – 15, also known as Agent A0-3959X.91 – 15 is an extremely potent and virulent mutagenic pathogen, composed of millions of small micro-organisms, that was manufactured by the Engineers as a biological weapon, presumably for military purposes. Due to its volatile nature at ambient temperature, the Engineers housed the pathogen within Steatite Ampules.

The primary purpose of the Chemical A0-3959X.91 – 15 pathogen is to cleanse planets of unwanted non-botanical life forms. Once exposed to another organism, the virus begins mutating the host by rewriting their DNA. The host becomes extremely aggressive and seemingly mindless as it attacks any living thing in sight. The chemical's induced mutations seems to be random with it never creating the same effect, however, it often does seem to accelerate the healing ability of its host though anyone or anything with cancer will have their condition greatly accelerated to the point of eventual death. It was shown that the Engineers created the chemical thousands of years ago on LV-223 for the purpose of wiping out entire planets. Somehow, the Engineers themselves were exposed to the pathogen, wiping out the entire Earth invasion force, except for one still in stasis.

The pathogen also mutated several worms found in the Engineer temple, turning them into the aggressive Hammerpedes. These creatures exhibited acid blood and the ability to regenerate lost body parts, though the latter is an ability commonly found in flatworms on Earth. However, the regeneration of Hammerpedes is much faster than that of normal flatworms, suggesting that the pathogen can enhance a host's natural abilities.

According to David, who spent a decade extensively studying the pathogen and its effects, the virus is designed to infect non-botanical organic life. As demonstrated on Planet 4, the virus is also capable of killing outright instead of merely infecting. When the pathogen infects a viable host it gestates a hybridized parasitic life form which may kill the host upon emergence.

In researching, Weyland Industries managed to uncover an information manual written by the Engineers concerning the chemical. Linguistic components from the original document were translated by a Weyland Industries' cybernetic individual. The document was later declassified.

Upon arriving on the Engineer home world, David deployed the steatite ampules over a large settlement, the pathogen petrifying every Engineer present and drastically affecting the environment by exterminating or mutating non-botanical organisms, giving rise to highly aggressive predators like Neomorphs and Protomorphs.

Engineers
The Engineers, also known as Space Jockeys are a race of ancient, legendary extra-terrestrial humanoids. They possess some of the most advanced technology in the entire galaxy, with special emphasis placed on their skills in Genetic Engineering. Credited with the creation of mankind, Engineers are believed to have been beneficent Creators of sorts who sailed the stars terraforming primordial celestial bodies and seeding them with the foundations of biological life. As such, they are revered by some as gods by the species they created. The name "Engineer" was given due to the life-form being responsible for "engineering" the human race. The Engineers are extremely pale-white, hairless and humanoid due to their subterranean nature, with two arms and legs. The veins underneath their skin are visible, and their eyes are in the shape of oblong plus-symbols.

The Engineers are 10 feet tall and breathe oxygen just like humans. They also seem to be extremely strong and resilient from simple punches and was impervious to gunshot damage at close range. However, Engineers are outfitted with a biomechanical pressure suit that probably also increased its strength, speed and durability by working as a biotechnological power suit. Though not much is known about the Engineers, it is shown that the Engineers have displayed advanced forms of culture that exist within their society, such as language, visual arts, music and clothing.

The Engineers' writing system is strikingly similar to Mesopotamian cuneiforms that can be found in the middle-east, and their hieroglyphs are identical to what is found in Egypt, and other places on Earth. As such, human DNA and Engineer DNA are virtually identical. The Engineer's reasons for doing this is unknown, though they seem their race do not hold any positive regard for their descendants. Dozens of cargo ships carrying the weaponized black liquid were set to launch for Earth to release the pathogen and let it wipe out humanity, only to see the Engineers somehow lose control of their intended weapons and perish. The Engineers are a technologically-advanced race. They are extremely advanced in genetic engineering and have built their own spaceship.

The cargo hold of the Engineer's ship was filled with Xenomorph Eggs, which are held in stasis beneath a blue electrical mist. It has been speculated by fans that the Space Jockey's race are the creators of the Xenomorphs because of the similarities in design between the spaceship and the biomechanical Xenomorphs.

Little is known about the Engineers' history beside them being transcendent beings, but the Engineers are shown to be the "creators" of the human race as they visited Earth during its primordial state. The Engineers continue to visit Earth multiple times to secretly observe the human race's development, presumably to pursue further unknown studies on humanity. The Engineers are a technologically-advanced race. They are extremely advanced in genetic engineering and have built their own spaceship. The cargo hold of the Engineer's ship was filled with Xenomorph Eggs, which are held in stasis beneath a blue electrical mist. It has been speculated by fans that the Space Jockey's race are the creators of the Xenomorphs because of the similarities in design between the spaceship and the biomechanical Xenomorphs. On the other hand, it is stated that Space Jockey's race found them on LV-426, and there has been no conclusive evidence shown and supporting that the Space Jockey's race created the Xenomorphs. Clearly, however, the Space Jockey's race have advanced technology, leaving open the possibility that they had a hand in the Xenomorph's creation.

While exploring the interior of the Engineer-constructed spaceship, David observed a type of slime with an energy inside that was used to press buttons, activate doors, and objects. Also show there was one Engineer alive in a form of stasis similar to that used by Humans. Engineers were capable of holograms, terraforming atmospheres, bio-engineering, and perhaps even accelerating evolution.

At some point approximately 2,000 years before, the Engineers stationed on LV-223 initiated a plan to wipe out humanity for reasons unknown by releasing the black liquid pathogen they had created. However, they apparently lost control of the pathogen and led the Engineers there to die off. Four surviving Engineers took refuge within their ship, storing themselves within their hypersleep chambers. However, only one of them survived.

Engineer Technology
Steatite Ampules: Steatite Ampules were cylindrical enclosures designed by the Engineers to establish and maintain the controlled environment necessary to store Chemical A0-3959X.91 – 15, due to its highly unstable nature at standard room temperature. The exterior surface of a Steatite Ampule was engraved with an informational placard.

Within an Ampule, the A0-3959X.91 – 15 was contained by four conical-shaped glass vials. This was to ensure the agent's ability to retain infectivity and virulence after a prolonged period of storage. All Ampules were to be aligned in rows, kept at a distance of 0.9652 meters apart from one another. Errors in temperature stability seemed to be amplified with an increase or decrease in this distance. As was the nature of the weapons, they were designed to release the AO-35959X.91-15 due to sensing sudden environmental changes, and as observed, deploy the chemical when sensing viable lifeforms nearby.

Sarcophagus: The Sarcophagus is an Engineer hypersleep chamber capable of keeping an Engineer alive for a great length of time. In a Sarcophagus, tubes supplying oxygen and nitrogen connect to the Engineer's bio-suit. When not in use, these units are covered.

Juggernaut: The Juggernaut is a type of extra-terrestrial spaceship used by the Engineers. Its exact purpose and function is unknown, though it seemed to be a commonly used multi-purpose transport vehicle and the Engineer's primary method of interstellar travel.

Juggernauts are large, asymmetrical, wishbone-shaped spaceships, with thickened central sections between two horns, which bend upwards. The ships typically have numerous places of entry, though they have three large openings near ground level between two horns, leading into the interior of the Juggernaut. Juggernaut interiors are designed in a highly bio-organic fashion, resembling more of a living organism than a space-going vessel, with skeletal walls, circular gangways and steep passageways. A Juggernaut's bridge consists of 4 Sarcophagi, a control mechanism made out of some sort of biological-like material, which is activated through the use of an Engineer flute and the pilot's seat on the center of the bridge. It is unknown how many crew-members are typically required to man the whole ship, though the vessel seems to be able to function reliably with as little as a single pilot. Judging from the sheer size of the ship, however, it would be possible for the ship to have easily carried hundreds of thousands of passengers.

Vast Black Ship: The "vast black ship" was a spaceship used by Engineers that visited Earth during its primordial state. The ship was leaving Earth's atmosphere as a lone Engineer prepared to sacrifice himself by ingesting a black substance, causing his entire body to disintegrate and seeding the planet with his DNA, thus hastening evolution upon the Earth.

Engineer Temple: The Engineer Temple was one of many structures located on the planet LV-223. It is believed that the structure served as a pathological research facility used by the Engineers, while it is also believed is "just another tomb." The temple is a large, complex structure containing many chambers and tunnels, some of which extend underground. Part of the temple functions as an atmospheric processor able to convert the toxic air of LV-223 into a breathable environment for humans.

The temple also has several chambers, which stores the Engineers' ships and the "urns" that contained the pathogen. Murals were seen in the temple, particularly in the "ampule room." When the Prometheus crew came inside, David touched the black goo, and the murals immediately changed. On one strange mural it showed what appeared to have figures in the background. When a human is inspected by the mural, it notices a green crystal on a platform in front of the mural. Another showed an Engineer with his hand on either an alien creature, a deformed Engineer, or perhaps the alien in the giant mural. At some point approximately 2,000 years before, the Engineers stationed on LV-223 initiated a plan to wipe out humanity for reasons unknown by releasing the very substance they used to create the human race on Earth. However, they apparently lost control of the pathogen, which led the Engineers there to die off. Four surviving Engineers took refuge within their ship and stored themselves within their ship's Hypersleep Chambers, but only one of them survived.

Xenomorph Prime
Xenomorph Prime is the home world of the Xenomorphs along with several other alien species. Xenomorph Prime is at least the size of the Earth and has three major continents and a small ocean. The hive area of the planet is full of Xenomorphs, and most of the landscape is covered in an enormous Hive, although some deserts, mountains, oceans and some other landscape features are not covered in the Hive structure. There are most likely multiple Xenomorph hives that support one another to keep the planet under their control. Although Xenomorphs are the dominant species of the planet, there are several non-Xenomorph species on the planet which are just as dangerous, if not more so. Human and Predator spawned Drones/Warriors as well as Runners won't be naturally found on the planet, this is because these Xenomorphs require a host not native to the planet and thus it would not be their "home world" unless the hosts required for above were to visit or be taken to the planet.

The Xenomorphs on the planet have been known to spread to different neighboring worlds, and many Xenomorphs, ranging from small Facehuggers to even Queens, are kidnapped and taken off-world by Yautja, their natural enemies, to begin a hunt on worlds such as Earth. Although Xenomorph Prime is mostly covered in Xenomorph hive webbing, it does include deserts, mountains, oceans, savannas, forests, and tundras. Xenomorph Prime is home to the Queen, the supreme leader of the Xenomorph hive, which is considered to be one of the strongest creatures in the galaxy.

Wildlife:

Xenomorphs: The deadliest semi-sapient species in the galaxy. Xenomorphs are one of, if not the most, fierce and vicious creatures on the planet. Xenomorphs are at the top of the food chain and have few natural 'predators' or enemies.

Xenomorph types known to live here:

Facehuggers

Queen Facehuggers

Chestbursters

Xenomorph Queens

Xenomorph Life Cycle
Life cycle of the species Xenomorph is a complex process involving several distinct stages and the use of a living host organism as a vessel inside which the infant Xenomorph gestates. The cycle, and in particular the use of hosts that invariably perish when the infant Chestburster forces its way through their ribcage, is often considered the species' signature aspect and is the characteristic for which they are most well known. The Xenomorph life cycle is comparable in many ways to certain parasitoidal insects found on Earth, such as wasps which lay their eggs on live prey that are then consumed by the hatching larvae. However, the cycle is at the same time unique, particularly with regards to the manner in which the infant Chestburster stage develops — instead of simply being implanted as a fetus and growing within the host, the Chestburster is actually more akin to a cancerous growth that assembles itself using the host's own cells and biological material as building blocks. The corresponding transfer of genetic material, referred to as the DNA Reflex, causes the physical attributes of the adult creature to vary.

The Xenomorph life cycle consists of five primary stages: the Queen, the Ovomorph, the Facehugger, the Chestburster, and finally the Xenomorph. The adult stage can be further subdivided into a number of forms or castes, each with differing physical characteristics based on age, function or the genetic makeup of the host creature.

Egg Sac/Ovomorph (Egg)/Eggmorphing: The Egg sac is the part of a Xenomorph Queen that creates and then lays Eggs. While a Queen is perfectly capable of surviving without an Egg sac, she cannot produce more Eggs in this state. A Xenomorph Queen's egg sac is enormous, easily dwarfing the size of her body. Typically stretching for many tens of feet, the structure is analogous to the large egg-producing abdomen of queen termites. Eggs are produced inside the Egg sac constantly in a fashion similar to a mass production line, first forming at the base of the sac, where it connects to the Queen herself, and developing as they move towards the rear end. Finally, the developed eggs are laid by an ovipositor at the egg sac's tip. The Ovomorph or Egg is typically considered to be the first stage of the Xenomorph's life cycle. Eggs are laid by a Queen and are large, ellipsoidal leathery objects between two to three feet high with a four-lobed opening at the top. As a host approaches, the Egg peels open, a Facehugger extracts itself from within and attaches itself to the host's face. Eggmorphing is a process by which Xenomorphs are capable of transforming hosts into an Egg.

Facehugger/Trilobite: A Facehugger is the second stage in the creature's life cycle. As its name suggests, it attaches itself to a victim's face, and its sole purpose is to impregnate them orally with the beginnings of a Xenomorph embryo. Upon making contact with a potential host, the Facehugger quickly renders them unconscious through the use of a cyanose-based paralytic chemical. The Facehugger then inserts its proboscis into the host's mouth and down its throat, supplying it with suitable atmosphere whilst simultaneously implanting the next stage of the creature's life cycle. Attempts to remove Facehuggers generally prove fatal, as the parasitoid will respond by tightening its grip and suffocating the host, while the Facehugger's acid blood prevents it from being safely cut away. Once the Xenomorph embryo is safely in place, the Facehugger detaches, and dies. The Queen Facehugger is a special variant of the Facehugger and has the ability to lay a Queen embryo inside a host, as well as a further standard embryo inside a second host, a tactic designed to give the unborn Queen an immediate "bodyguard" in the form of a normal Drone.

A Trilobite is a massive Facehugger-like alien that results from a host being infected with the black liquid and engaging in sexual intercourse with another host. Similar to a Facehugger, its primary purpose appears to be to implant a Deacon into a host such as an Engineer. It is not made clear if the creature was conceived by their intercourse or if the infant creature merely moved into a human from the infected host. The creature gets out of its host "naturally", as the host removes it prematurely. However its exaggerated movements prior to this suggest that it bursts out from the host's abdomen like Chestbursters. The immature Trilobite resembles a big four-armed squid, however it is extremely aggressive and grows to an enormous size with no biomass to take in, in very little time. As an "adult", it resembles an extremely large Facehugger (even larger than Engineers if the tentacles are taken into account), but with many differences. It comprises many large tentacles which are strong enough to subdue an Engineer and also has six smaller tentacles that shoot out around its mouth. Unlike a Facehugger, it does not leap onto a victim's face but instead grabs it with its tentacles and attempts to subdue it long enough to impregnate it, after which it settles its considerable body mass on top of the host's body. At the centre of its body is a large fanged mouth inside which resides a large feeding tube used to impregnate its host. At the back of the Trilobite, are holes, likely used for breathing or redirecting the air into its host. During impregnation, hosts lose strength and fall unconscious, like normal Facehugger victims. The impregnation process seems to be the same as the Facehugger's, but when a Trilobite impregnates a host, it gives birth to a Deacon. The Trilobite also dies after it impregnates a host, like Facehuggers. The Trilobite lacks a tri-lobed body and bears no resemblance to the prehistoric creature of the same name.

Chestburster/Bellyburster: Arguably the most biologically intriguing stage of the Xenomorph's life cycle, the Chestburster is not implanted into the host as an embryo but is in fact akin to a cancerous growth. It begins as a tumor that causes the host's body to literally construct the infant creature from its own biological material. This process causes the developing embryo to take on some of the host's physical traits via a process known as the DNA Reflex, including bipedalism, quadrupedalism or even possessing the mandibles of a Predator and other body structure changes. Over the course of 1–24 hours, and sometimes up to several days in the case of some Queens, the tumor develops into a Chestburster, at which point the creature emerges, violently ripping out the chest of the host, killing it. Owing to its cancerous nature, Chestburster development is typically fatal for the host even if the growing organism itself is surgically removed.

The Bellyburster is another Chestburster that bursts out from the victim's stomach. They seem to be more or less identical to traditional Chestbursters, the only difference being their different gestation characteristics. A Predalien could even force embryonic Xenomorphs down a host's throat. The victims appear to be only females. Later, multiple larvae would burst out from the victim's stomach. Functioning as juvenile Queens, Predaliens utilize these multiple offspring to quickly increase Xenomorph populations and build a hive, presumably before molting into a full grown, egg-laying Queen.

Growth and Maturity: Immediately after the Chestburster erupts from the body of its host, it will typically flee and find a secure location in which to molt into its adult form. At this stage in its life, the Xenomorph is in fact quite vulnerable. Initially, the Chestburster is less than 1 foot (30 cm) tall. However, it soon undergoes a dramatic growth spurt, reaching adult size in a matter of hours.

Neomorph Life Cycle
Egg sack: The initial stage in the Neomorphs' life cycle is the egg sack, a fungus-like growth found in clusters throughout Planet 4 as a result of their contamination with the black liquid.

Spores: If an egg sack is damaged or otherwise touched by a host, they spew out a cloud of microscopic dust-like spores that conglomerate into an airborne cloud-like mass. The spores possess a rudimentary hive intelligence and infect the nearest viable host organism through an open hole such as ears or nose. The spores themselves are extremely small in appearance, no larger than a grain of sand, though they can still be vaguely visible when gathered together. They appear to be extremely tiny parasitic insects when viewed under a microscope.

Bloodburster: Once inside a host organism, the spores burrow into their body, extend an ovipositor, and inject eggs. These eggs re-write the DNA of the host and starts the growth of an amnionic sac, within which a Bloodburster rapidly gestates in a matter of hours, before violently emerging and killing the host. If the amniotic sac is located in a difficult-to-emerge-from location, the Bloodburster can use the sharp dorsal spines and pointed head to pierce and rip through flesh.

Growth and Maturity: Immediately after the Bloodburster claws its way out from the body of the host, it will typically flee and find a secure location in which to evolve into its adult form similar to a Xenomorph. Like the Xenomorph at this stage in its life, the Neomorph is also quite vulnerable. However, it soon undergoes a dramatic growth spurt, reaching adult size in a matter of hours.

Neomorph: Now as vicious carnivores, Neomorphs will attack, kill and devour any victim, growing rapidly and reaching full maturity in a matter of hours. In their juvenile stage Neomorphs are small and quadrupedal, but upon reaching maturity, they are large, deadly and bipedal.

Species
Drone: The Drone is the most basic and common form of Xenomorph found in the hive. Its form acts much like bees, wasps or ants. The Drone's main function is to keep the hive functioning properly and to gather hosts for impregnation. They are almost identical to Warriors in appearance with the exception of their smooth, domed skull, and their tails, which end in a stinger-like tip as opposed to a large blade.

Warrior: The Warrior is the primary assault caste of the Xenomorphs. They are fast, incredibly strong, reasonably tough, and savage combatants. Even in death the Warrior is dangerous, as its highly pressurized bloodstream will cause it to burst apart when killed and drench nearby enemies in acid. Warriors have ridged heads, as opposed to the smooth carapace of the Drone, but are otherwise virtually identical. Because of this, Warriors are often said to simply be the mature life stage of the Drone.

Runner: The Runner is a Xenomorph spawned from an animal host. The creature itself shares the same basic physical conformation and instincts as bipedal Xenomorphs, although they typically adopt a different posture, primarily running on all fours in a quadrupedal manner and possessing digitigrade hind legs. They also lack the spikes of Xenomorphs and are more red-brown when compared to black Xenomorphs. They can also spit acid from their mouths.

Queen: The Queen is the matriarch of the Xenomorph species as well as the biggest and bulkiest. They are significantly larger and stronger than basic Xenomorphs. They are approximately 20 feet tall when standing erect and 53 feet in length. Their body structure differs also, having two smaller arms located on the chest, a larger inner jaw, two sets of dorsal spikes and a much longer, segmented tail. The Queen's head is shaped like a crown and larger than other adult Xenomorphs. The exact shape of the crown can vary from Queen-to-Queen. Unlike other Xenomorphs, the Queen also has high heel protrusions from its feet. Queens possess an immense Egg sac attached to their lower torso, similar to the enlarged abdomen of a queen termite. Unlike insect queens, there appears to be no need for drones to fertilize the Xenomorph Queen. When attached to its Egg sac, the Queen is essentially immobile and her body is supported by a biomechanical "throne" that consists of a lattice of struts resembling massive insect legs.

Deacon: The Deacon is a juvenile Xenomorph-like creature spawned from a Space Jockey/Engineer host. It has a blue smooth body, four fingers, a thumb and plantigrade legs. Its mouth possesses two different teeth sets, the top Jaw having teeth typical to herbivores, while its lower jaw had sharp teeth spread apart, the gum that protrudes behind the top possesses sharp teeth. The biggest difference between Xenomorphs and the Deacons is the host they come from. As with all Xenomorphs, they gain different characteristics from their hosts. It is important to note how the birth of this creature is different from the majority of Xenomorph births - it was born with arms and legs, while most other Xenomorphs born of humanoid hosts lack legs and arms before maturing. Instead of having a second inner jaw like Xenomorphs, Deacons have a single set of protrusible jaws more akin to those of a goblin shark, where the upper jaw can unhinge and move forwards. Deacons also lack any biomechanical features, being nearly completely smooth, with exception of some ribs showing. Unlike Xenomorphs, Deacons use the sharp back end of their head to tear their way out of the host.

Predalien: The Predalien is a Yautja/Xenomorph hybrid spawned from a Yautja/Predator host. It is apparently rare and is regarded by the Yautja themselves and an affront to their species. Predaliens feature Yautja characteristics such as dreadlock-like appendages on their heads, Yautja-like mandibles, and occasionally comparable skin colour and vocalizations. They are also big, hulking creatures possessing greater strength than both Predators, humans and Xenomorphs. Predaliens also have thicker tails than regular Xenomorphs. One Predalien has been capable of bypassing an Ovomorph and Facehugger reproductive cycle altogether, being able to implant multiple embryos within a single host directly through its inner jaw. This trait apparently allows the creature to build an army of Xenomorphs before it becomes a matured Queen and enters its sedentary condition with an Egg sac. Predaliens notably take after their host to a greater extent than Xenomorphs, possibly because the Predator's genetic code is significantly more potent. This could also explain why some Predaliens have been known to carry out ritualistic mutilation of their prey, perhaps as some form of instinctual throw-back to Yautja customs passed down genetically from the host.

Newborn: The Newborn is a mutated human/Xenomorph hybrid that was produced when the Cloned Queen aboard the USM Auriga developed a reproductive cycle, a perversion of the human uterus (and related organs). The Newborn was considerably bigger and taller than a normal Xenomorph and notably does not possess a faceless, highly elongated skull typical of the species. Instead, it has a far more ugly face, including eyes, a nose, a fleshy human-like tongue instead of a Xenomorph's inner jaw, and a far more humanoid skull-like face that showed only minor elongation at the rear. The creature also lacked the distinctive dark, biomechanical exoskeleton common to the species, instead being covered in soft, flesh-coloured human-like skin. The Newborn is incredibly strong as it possessed superhuman strength and is able to jump huge distances or crush a victim's head with its bare hands. It shared little association with its Xenomorph brethren, going so far as to kill the Cloned Queen that bore it, and apparently viewed Ripley 8 as its true "mother".

Cloned Xenomorph: Cloned Xenomorphs are Xenomorph clones kept aboard the USM Auriga by United Systems Military scientists. They descended from the Cloned Queen extracted from Ripley 8. Due to imperfections in the cloning process, the Queen and her offspring were not true Xenomorphs but subtly altered hybrids, mutated through the inclusion of human DNA in their genetic makeup. While the Cloned Xenomorphs generally resembled normal Xenomorphs, they possessed several notable differences that made them unique. Their necks were fleshier in appearance compared to the biomechanical look of other Xenomorphs, and they displayed some quadrupedal traits akin to the Runner caste, as opposed to adopting the primarily bipedal stance of other Xenomorphs. There were also slight differences in the shape of the head, which was narrower, with a longer muzzle and more prominent chin. Additionally, both the Cloned Queen and her Drones were green-brown in colour, with a shimmering, insect-like quality to their exoskeletons.

Neomorph: The Neomorph is an albino endo-parasitoid Xenomorph-like creature that share some characteristics with the original Xenomorph, most notably their process of gestating inside a living host organism and their elongated heads. They are also otherwise quite different. The Neomorphs were the result of the local ecosystem on the planet to which David travelled after leaving LV-223 becoming altered by the black liquid. Specifically, the liquid caused small, black, spherical, fungus-like egg sacks to form on the ground. When disturbed, these egg sacks would release a cloud of microscopic insect-like spores into the air that would then enter a host organism through any open hole such as nostrils or ears. Once a host is infected with the airborne contagion, the spores would enter the bloodstream and proceed to cause a Bloodburster to grow inside of them until they violently puncture the skin and claws their way out of the host's body. This process is notably similar to the Xenomorph Chestburster, although the exact point of emergence varies depending on how the host was infected. As with Xenomorphs, the appearance and characteristics of the Neomorph depend on what sort of animal it was spawned from. When spawned from a human host, the creature is born with arms and legs and initially moves in a quadrupedal manner, but as they grow, the Neomorph adopts a bipedal stance. The creature has pale, white-grey skin with a somewhat translucent appearance. The Neomorph features a fleshy tail tipped with spikes, which can be used as a devastating slashing and battering weapon, and a large number of fangs in their mouth, which appears circular when closed. Notably, individual Neomorphs appear to display physical variance. For instance, one of the creatures featured a pair of sharp, bony spikes on their back that assisted them in breaking out of their host, whereas the other individual encountered lacked these features. Their blood is thick and yellow, but notably not acid. In terms of behavior, the Neomorph is far more feral and animal-like than a typical Xenomorph, to the point that even their newborn form is highly aggressive and will attack anyone on sight. Their animalistic nature may suggest a lack of intelligence in comparison to their counterpart, however, they are capable of being deliberate and stealthy. Neomorphs are notably seen consuming the flesh of humans they have killed, though Xenomorphs have not been depicted doing this. Unlike a typical Xenomorph, Neomorphs do not possess an extendable inner jaw which can be used to attack, instead their "gums" extend out in a manner similar to goblin sharks. Also, while the teeth of a Xenomorph's outer jaws are usually visible, a Neomorph's jawline is nearly invisible when closed.