Xenomorph or Internecivus raptus is a highly evolved brood species originating on an unknown planet.
standing upright, the Xeno Morph are bipedal in form, though depending on their host species, they will either adopt a more hunched stance, or remain quadrupedal when walking or sprinting. Their overall stance and general behavior is a result of the mixture of the DNA of the embryo and the host. They have a skeletal, biomechanical appearance and are usually colored in muted shades of black, gray, blue or bronze. Their body heat matches the ambient temperature of the environment in which they are found, so they do not radiate heat, making them indistinguishable from their surroundings through thermal imaging. In most of the films, adult Aliens are capable of running and crawling along ceilings and walls.They have great physical strength, having been shown to be capable of breaking through welded steel doors in numbers.
Aliens have segmented, blade-tipped tails.which they wield effectively as a weapon
the Aliens are not sapient “tool-makers” – in other words, they lack a technological civilization of any kind, and are instead primal, predatory creatures with no higher goals than the propagation and self-preservation of their species, including the elimination of other lifeforms that may pose a threat to their existence. Like wasps or termites, Xenomorphs are eusocial, with a single fertile queen breeding a caste of warriors, workers, or other specialists strains. The Aliens’ biological life cycle involves traumatic implantation of endoparasitoid larvae inside living hosts; these “chestburster” larvae erupt from the host’s body after a short incubation period, rapidly mature from juvenile into adulthood within hours, and seek out more hosts for implantation.
The Xenomorph is known for its highly aggressive nature and ferocious loyalty to their brood. They have shown exceptional problem sovling ability as well as a basic understanding on many technologies.
The physical form of a Xenomorph can vary depending on its life stage, hive, caste, age, and host, as well as varieties which have been genetically engineered by host species or genetically grown. The typical Xenomorph start its life cycle as an egg-like creature which, when detecting the presence of a potential host, opens up to release the second stage: a small quasi-arachnoid life form (Facehugger) which launches itself onto the hosts face and impregnates it with an endoparasitoid larva. This parasite then consumes the host from within and exits the body as a vaguely worm-like organism, before growing very quickly and developing into an adult Xenomorph.
Although numerous varieties exist, adult Xenomorphs all tend to share some common traits: a vertebrate-like body, a protective exoskeleton, a long flexible tail, an elongated domed head, with nearly invisible eyes near the mouth, and a toothed maw hiding a proboscis-like inner mouth. Little is known about their biology, but it is known that they eat with their inner or secondary mouths, not their outer mouths. This mouth is somewhat similar to the pharyngeal jaw of a moray eel. They also bleed an unknown and extremely corrosive Fluoroantimonic acid type of fluid. It is dull yellow in color and often referred to as “blood”, although whether it’s used to transport nutrients through the body and/or just serves simply as a defensive mechanism is not clear.
While the extremely corrosive fluids and tremendous resilience displayed by the creature might suggest an alternative kind of biochemistry, the fact that the Xenomorph not only feed on Humans, but actually develop inside them, strongly suggests that its biology is carbon-based. The ability to inherit traits from its hosts also suggests that it incorporates genetic material from them, implying that the Xenomorph either has DNA, or is able to read and convert DNA into whatever means it uses to store genetic information.
. Xenomorphs appear to possess a roughly similar intelligence to that of a typical primate, but have shown to learn relatively quickly, utilizing the situation around 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 its social behavior and manipulation of human technology, such as cutting the power of the LV-426 colony and operating an elevator.
Xenomorphs have demonstrated little emotion, though they are not completely devoid of fear
The adult Xenomorph is a living weapon,(tail is used as 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 its 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 bio-mechanical-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.