Xenomorph

The most notable feature of the Xenomorph species is the elongated, banana-shaped head. A potential explanation for this curious shape may be that the head may store muscles required to power the Xenomorph's inner mouth.

In terms of eyesight, the Xenomorph appears to be entirely eyeless. However, there are features on its head which could represent eyes, which are usually hard-to-see due to the fact that they're small and the same black color as the skin.

Other proposed conjectures include that the eyes might be similar to a desert-burrowing lizard's eyes; meaning that they lay under a thin layer of skin, yet are deep enough that they are not visible from the outside. In that case, their eyes could be hidden behind their black carapace and they see through it, similar to a one-sided mirror (except in this case no one can see in, but the Xenomorph can see out). Some species of Earth fish, such as the Barreleyes, see through a transparent layer of skin; it is possible Xenomorph vision is similar. Another idea is that their whole head might represent one big insect-like eye.

Eyeless or not, it is widely assumed that a Xenomorph identifies enemies by sensing pheromones. This has never been explicitly confirmed nor denied, but a Drone will not kill a host that's already infected, so they must have some way of detecting the presence of the unborn parasite within.[8]

The secondary jaws (also known as the inner mouth, double jaw, or maw) are another disturbing feature of the species. It's assumed that they're powered by extremely strong muscles inside the creature's elongated head, that enable it to be quickly launched and retracted, similar to the tongue of a chameleon. The albino Xenomorph Drone has a very long inner mouth that can secrete resin that's used to build the walls of their hives.

The inner mouth is typically the Xenomorph's close-combat weapon, as opposed to its long-range tail. The Xenomorph lashes it out of its outer mouth, and it destroys anything it hits, being able to put a hole in a thickened Yautja skull and still have enough momentum to plunge another hole through the back as it escapes. Yautja take them as souvenirs of their kills.

The secondary jaw is powered by muscles, as seen when a Yautja rubs a part of the interior (resembling the gills of a crab), a feature that can be seen from the external midsection on each side of the head, ovular in shape. Muscles rub along here, letting the mouth be pushed out like a piston through the target the Xenomorph has acquired.

The Yautja-spawned Xenomorph (a.k.a. "Predalien") has the ability to use its inner mouth to implant chestburster embryos directly into a host's throat, like a facehugger. Since that particular Predalien was also on her way to developing into a Queen, it's possible that all future-Queens have this ability.

Along the back of most Xenomorphs' bodies are a series of appendages that appear to have no clearly-defined function. It's still in debate what they are used for, with theories ranging from sensory organs to communication organs, to breathing apparatus, to defensive mechanisms, to structures that dissipate heat, to storing substances their bodies need, or to provide structures to carry around the young, underdeveloped chestbursters, the eggs or the facehuggers or as a counter weight to keep them from falling over when running. None of these ideas has been confirmed or denied so far.

One theory is that the four back appendages are used as a kind of radar that the alien utilizes to see through extreme environments or detect movements. It is also said that the dorsal spines are used to secrete and possibly store the resin used to build their hives.

It is interesting to note that Xenomorph Drones have been observed to bury themselves in the ground, yet their spines are still shown just breaking the surface[9], implying some use when connected to the environment. This may be either biological (breathing, heat exchange, etc.) or sensorial (detecting the vibrations of marines walking on the ground above).

1. Xenomorphs produce a thick, strong resin, which they use to build their hives and cocoon victims. Cocooning is a trait used by Xenomorphs to reproduce quickly. A Human, or any other creature, if dragged away, may have a cocoon of saliva and resin placed over them (their face left free), usually in an area where the Queen has produced a large quantity of eggs, so that the facehuggers are able to latch onto them easily and deposit a Xenomorph larva inside their chest. Much like termites, they mix their viscous saliva with solids. It shows amazing heat and moisture-retaining qualities.
2. Due to the absence of clearly visible eyes, it is possible that the creature uses echolocation to see its environment, much like bats. It may be for this reason that Xenomorphs hiss almost constantly, though there is evidence that they can detect light and darkness as well. Xenomorphs may be able to find their prey through electro-reception. This is the method sharks use to detect even the most hidden prey. Creatures with the electro-reception sense can detect the electromagnetic field all animals produce, allowing them to locate their prey by its heart beats, even if the prey is immobile. This would explain how Xenomorphs always know where the Humans are. Furthermore, the Xenomorphs can also detect whether a potential host is already infected, likely by sensing pheromones.
3. It is accepted that the tail is an offensive weapon and little more. Though the creature can and will run on all four appendages, it often stands on its two hind legs so it can reach for its prey with its arms. While standing, it has also been seen to impale its victim with its tail, even to the point where it can raise a creature heavier than itself to eye level, possibly in preparation for a face-bite using the secondary jaws. This would clearly be impossible if the tail was needed for balance, as the already-shifting weight would be too awkward, causing the monster to fall.

in all stages of their life cycles, have been said to have vulnerabilities to heat. The use of molotov cocktails and flamethrowers constitutes an effective technique to drive them off. The only Xenomorph not vulnerable to fire is the Predalien, which can secrete a layer over its body that cannot be ignited, although they are still visibly pained by temperature extremes, such as liquid nitrogen.

A rapid succession of extremes in both high and low temperatures apparently causes a thermal shock effect on a Xenomorph's exoskeleton. Xenomorphs are capable of adapting themselves to cold environments with little discomfort. However, the alien Queen is particularly vulnerable to fire, for unknown reasons.

Depending on the circumstances, Xenomorphs are shown to be both invulnerable and vulnerable to small firearms, ranging from 9mm to 5.56mm. This is seen when Vasquez and Lt. Gorman find themselves trapped in the ventilation between advancing aliens coming from both directions. Gorman fires with his pistol on one of them with no effect at all, instead it looks like the ammunition bounces off (presumably from the head carapace). In another occasion, however, Vasquez holds an alien at gun point and fires her pistol at the head, which apparently goes through and the alien rattles away, obviously damaged. High-caliber firearms, with the explosive rounds of a M41A Pulse Rifle may cause the creatures to detonate. High-energy beam weapons, such as the plasma weapons used by Yautja, appear to be the best way to kill the Xenomorphs since it can blow them off with a single shot and at the same time vaporize their acidic blood, though pulse rifles appear to be the best way to repel large hordes of them since they can fire non-stop and are not prone to being destroyed like the plasma weapons.

Xenomorphs are not invulnerable to melee weapons, although such equipment is likely to be destroyed upon contact with their acidic blood, unless the weapons are made from Xenomorph's bones.

Most Xenomorphs appear to possess an intelligence level equivalent to that of a typical primate. It's well within their capabilities to learn relatively quickly, gathering information and making advantageous use of their environment. Although they do not demonstrate Human and Yautja-level intelligence as a species (such as abstract reasoning, introspection and technological advancement), their Queen appears to possess considerable acumen in her social behavior and manipulation of Human technology, such as cutting the power of the LV-426 colony and operating an elevator. While it may take considerable time for them to learn how to operate machinery[4], other Xenomorphs have displayed fast reasoning and the capacity to find creative, counter-intuitive solutions to problems, as exemplified by a group which, after noticing that they were being contained, intentionally murdered the weakest so that the acid of the Xenomorph's blood would eat through the floors.[5]

As the adult Xenomorphs are known to inherit physical characteristics from their hosts (for example, when a Yautja was infected, the parasite later developed into a "Predamorph" or "Predalien") it is possible that the intelligence level of the creature may be influenced by its host as well. Furthermore, being an eusocial species, it is possible that the intellectual capacity varies for each different caste.

Xenomorphs have demonstrated little emotion, though they are not completely devoid of fear, such as when they are in the presence of fire[6], which they are vulnerable to. They have also been shown to communicate pain through shrieks or screams when attacked.

It has been suggested that Xenomorph nests may operate under a hive mind, or a collective consciousness directed by the Queen, who can call back and give orders to her subjects, both telepathically and vocally with shrieks. In some cases, the Queen Mother Xenomorph communicates telepathically with potential hosts, inducing terrifying dreams.

The basis of any Xenomorph hive; the Drones are very much like worker bees or ants. Their main tasks are to keep the hive in good condition. Also, they seem to have the job of creating their nests with their own secretions.

They average in size at about 6–7 feet tall (~ 1.8 to 2.1 meters) standing on hind legs, and about 14–15 feet long (~ 4.2 to 4.6 meters), tail included. They have the basic body build of the Warrior, except that their dome is completely smooth, whereas the Warrior's dome is typically more ridged. Drones are smaller and somewhat more delicate than the Warriors, not considered quite as dangerous by Yautja standards, but striking fear into the heart of any Human.

Like all of their brethren, they have acidic body fluids, but only the Drone can spit this secretion onto prey over a short distance. Drones have an organ in their bodies that releases a sticky fluid that they can spit out of their mouth onto any surface. It can be used to harvest cocooned hosts for the Queen's facehuggers.

The adult Xenomorph is a living weapon, noted for their ferocity and deadliness in any condition. Once fully matured, they have great physical strength and agility. They are masters of stealth; a favored method of acquiring prey is to wait in a dormant state until an appropriate victim strays near, and then drop down silently from behind or use their tail to impale whoever walks by. The prey is generally blind to the fact that a Xenomorph is present, due to its propensity to camouflage itself within its nest walls or the surrounding artificial environment, given their biomechanical-like appearance. The Xenomorphs will also use their pitch black carapace to their advantage, lurking in the shadows whilst waiting for prey to stray too close.

Xenomorphs are shown to be able to take extreme amounts of physical damage that would kill any earthly life form. An example of this is a Queen that survived a multi-ton exo-suit falling on her from over 30 feet. Xenomorphs are capable of surviving with limbs shot off, stabbings and even shots through the head (though total decapitation kills them).

Adult Xenomorphs are quick and agile, and can clamber along ceilings and walls: a skill they exhibit freely whether they are evading others, attacking, or hunting. They can survive in extreme temperatures, are well-adapted to swimming, can respire in harsh atmospheres, and can survive in vacuum for indeterminate lengths of time. Their movements tend to be silent, and they do not radiate heat as their exoskeletal temperature matches the ambient temperature. They also salivate profusely. This saliva is not acidic. 2. Xenomorphs produce a thick, strong resin, which they use to build their hives and cocoon victims. Cocooning is a trait used by Xenomorphs to reproduce quickly. A Human, or any other creature, if dragged away, may have a cocoon of saliva and resin placed over them (their face left free), usually in an area where the Queen has produced a large quantity of eggs, so that the fa

The Xenomorph could only Make Screeching, and hisses.

Xenomorph is born in egg form, laid in place by the hive's Queen, through the use of a detachable ovipositor. The egg is thick and gelatinous, usually with several membranes attached to the outer layers. It can take nutrients from the ground to support the creature inside. The egg has vein-like structures running through it, showing that it is actually a living creature, sometimes known as an ovomorph.

The Xenomorph hatchling - called a facehugger - is protected by a thick fleshy layer at the top of the egg, where the "shell" peels open when the facehugger senses creatures nearby. The sense that detects suitable organisms has to be very specific in what it chooses to respond to. Perhaps this is why it takes so long to open: various sensory organs study the approaching organism. It seems to be capable of distinguishing synthetic life from organic life.

Sometimes Xenomorph Queens can lay eggs that contain up to four facehuggers.

The Xenomorph is born in egg form, laid in place by the hive's Queen, through the use of a detachable ovipositor. The egg is thick and gelatinous, usually with several membranes attached to the outer layers. It can take nutrients from the ground to support the creature inside. The egg has vein-like structures running through it, showing that it is actually a living creature, sometimes known as an ovomorph.

The Xenomorph hatchling - called a facehugger - is protected by a thick fleshy layer at the top of the egg, where the "shell" peels open when the facehugger senses creatures nearby. The sense that detects suitable organisms has to be very specific in what it chooses to respond to. Perhaps this is why it takes so long to open: various sensory organs study the approaching organism. It seems to be capable of distinguishing synthetic life from organic life.

Sometimes Xenomorph Queens can lay eggs that contain up to four facehuggers.

After the egg opens, the facehugger emerges and seeks out a nearby life form, latching onto its face, wrapping its tail around its airway, and implanting the Xenomorph embryo(s) by sticking a tube down the host's throat. This is seen sometimes when a facehugger is contained in water or lunging at a soon to be host.

It will coil its tail tighter around the airway to prevent premature removal, and an attempt to sever the fingers found that facehuggers possess the same green blood as an adult Xenomorph. The facehugger supplies oxygen to keep the host alive during the impregnating process. Once the embryo(s) has been implanted, the facehugger falls off, curls up, and dies.

Hosts usually fall into a short coma and wake up ravenously hungry. This can be explained as the embryo needing an immediate source of nutrients for its progression into the next stage of its life. Hours might pass between the host waking and their time of death. Yautja live the longest as a result of an extended incubation period. The reason for this is likely due to the genetic complexity of the host. The incubating chestburster requires more time for mitosis and cytokinesis due to the morphology of the Predalien.

However, in some cases, the hosts will awake not gradually but suddenly - just in time to be conscious of the Vagina/Anusburster's push out into the world. Their state of normalcy will last only seconds or minutes.

It's also proven that when a host awakens, there is some sort of a memory lapse in which they don't remember anything that has happened to them. This short-term memory loss is most likely a result of the temporary oxygen deprivation caused by the facehugger's tail, as it asphyxiates the host, the Facehugger will only impregnate females.