Alien
Real name: Xenomorph
Full name: Xenomorph
Creator: Dark Horse Comics
Alignment: Bad
First appearance: Alien (1979)
Place of birth: Your chest :)
Relatives: Alien Queen (mother)
Gender: Male
Race: Xenomorph XX121
Height: 8'0 • 244 cm
Weight: 375 lb • 169 kg
Hair color: No Hair
Skin color: Black
Superpowers: Agility, Cold Resistance, Durability, Enhanced Senses, Heat Resistance, Jump, Natural Armor, Natural Weapons, Stealth, Substance Secretion, Super Speed, Super Strength, Vision - Thermal, Wallcrawling
Stats: intelligence 75, strength 30, speed 40, durability 90, power 55, combat 60

History:
  There are several different phases to a Xenomorph's life-cycle, and what kind of adult Xenomorph will come into existence depends entirely on the being that it hatches from.   Eggs are lain by an Alien Queen, and exiting her body through an overgrown egg sack. The egg is a leathery sack approximately 2.5 feet tall. They are the very simple first step in the Xenomorph life cycle.    The Facehugger is what lays inside the egg. After a certain amount of time or if a host were to come too close to an egg, the Facehugger inside senses it through pheromones, and the egg opens up like a blossoming flower with the Facehugger launching itself out and planting itself onto the host's face.   Its long tail will wrap around the host's neck, and it will grip the head with its long eight legs - the Facehugger resembles a flat spider, in a sense. It has acidic blood and will bleed the acid on its victim if cut, and if attempts are made for it to be pried off, its tail tightens around the host's neck and a chemical will cause them to go into a cardiac arrest. The Facehugger also makes its host unconscious with oxygen deprivation. Once the Alien embryo is planted into the host's body, the Facehugger will detach, and die shortly afterwords. The host will wake up with no recollection to the event.    As time passes, the egg that was planted inside of the host will begin to stir. Then, it will begin to claw its way out of the host's chest, through the center of his ribcage. This obviously causes extreme pain, and as soon as the Chestburster breaks through, the host dies. It will then flee at top speeds to grow into its adult form and become even more dangerous. Its appearance changes in its variations, but it is small, with an elongated cranium, pale or dark skin, and a long tail - almost like a snake. Basically, Chestbursters are infant versions of Xenomorphs.    There are many different kinds of Adult Xenomorphs - however, they share the same general appearance. After the Chestburster has fled, it will wait and mature, shedding its old skin to reveal the darker kind, and its head will expand backwards into a crescent shape. It will grow arms and legs, its tail will lengthen and become much stronger (even to the point of being able to impale fully grown humans), and its blood will be much more acidic. Xenomorphs have many distinguishing features, namely:        Xenomorphs are the stuff of nightmares - they are vicious, cannot be reasoned with, and will never, ever give up. They operate entirely on the instinct to survive and propagate their race, but are surprisingly intelligent, able to remember through genetic memory their host's life and past. They communicate with a Queen and each other through changing pheromones and/or sub-supersonic sounds.   There are several variations of adult Xenomorphs, as they take on the characteristics of the host from which they hatch in order to better adapt to their environment. Countless varieties have been proposed throughout the various forms of media in which Xenomorphs have been depicted. Video games have added a considerable amount of these in order to create unique enemies of differing strengths and capabilities for players to fight. These variations are typically the result of Xenomorphs hatching from different kinds of hosts, but they also sometimes result from genetic tampering with the Xenomorphs by organizations seeking to exploit the race's unique abilities.  There are a select few that are most often depicted however, namely:     

Powers:
  Adverse extremes of temperature appear to have little, if any, affect on their physical prowess. In fact, physiologically they are incredibly hardy creatures — aside from being unaffected by temperature extremes that would quickly incapacitate or kill a human, they are capable of surviving in the hard vacuum of space, at least for a limited period of time. One Alien on Fiorina 161 was even known to survive several tons of molten lead being poured onto it.   The Xenomorphs' primary weapon is their inner pharyngeal jaw, which is capable of shooting from their mouth like a piston with sufficient 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 head, piercing through the skull and penetrating the brain; this form of attack is colloquially known as a "Headbite".   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 in color, 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.    The tails have been shown grasping prey and used as spears or flails.    Aliens have proven to be adept wall climbers, whether that is a result of digging into surfaces with their claws, finding hand-holds, or through some adhesive effect such as those used by geckos or insects has not been demonstrated.