Xenomorph

"The Xenomorphs had descended on Outworld from Lotos Prime long ago, but the dormant eggs they left behind were only recently found. The leader of the Tarkatan patrol had picked up one of the leathery orbs, only to have it burst open and its occupant latch itself to his face. Later, after the "face-hugger" had fallen off, the Xenomorph progeny burst from the unfortunate Tarkatan's chest, bearing characteristics of both Xenomorph and host. It eluded the rest of the Tarkatan soldiers and eventually killed them. The creature now roams Outworld, looking for more hosts. Its amazing strength and animal fury make Xenomorph almost unstoppable."

- Raiden about Xenomorph

The Xenomorph, also known as Alien, is a playable guest character in Mortal Kombat X.

Info
Xenomorph, or officially known as Alien XX121, is the primary antagonistic species of the MK franchise.

The Alien is a recurring major threat, and while his exact characteristics and appearance change between cutscenes, it remains one of the most dangerous creatures in the known universe.

The Aliens life-cycle is arguably their most iconic feature; they start life as an egg laid by the monstrous Alien Queen.

When a living being that isn't one of their own comes into physical contact or close range within the egg's radius, it will "hatch" and reveal a spider-like face-hugger. The face-hugger's purpose is to attach itself to the victim's face and orally transmit a Xenomorph sperm down the victim's throat. The victim remains in a comatose state during the process, which can take several hours. Once the process is complete, the face-hugger will detach itself and die. Gestation of the sperm is usually incredibly quick, ranging from a few hours to a day for it to fully develop.

Once the new Xenomorph is ready to hatch, it will violently force itself through the host's rib cage and tear itself out of their chest (which has led to this stage being called a chestburster). The larval Alien promptly flees from its host and seeks out a safe hiding spot as it rapidly molts into a fully-grown Xenomorph. The resulting adult can take on a variety of unique forms, depending on the species it was incubated in.

Xenomorphs are immensely hostile and aggressive towards other lifeforms. In most cases, they will either immediately attack other creatures on sight or take them to their nest for harvesting, but they may also stalk their prey for a time in order to ambush them later. Lifeforms that are not suitable for harvests are generally ignored.

The entire Xenomorph specie lives to propagate itself by using any lifeforms in whatever ecosystem they've infected to grow their numbers and spread even further. Every nest usually contains a Queen that will instruct the other Xenomorphs on their duties, acting somewhat like a hive mind - larger nests may also include Praetorians, advanced Alien variants that protect the nest from intruders. Regardless, they are still able to function without a Queen.

Xenomorphs are also known for their constant association with the Predator species. The latter views the Aliens as the "ultimate prey"; those few hunters who survive encounters with the Xenomorphs receive great praise from fellow Predators.

In Mortal Kombat X, a Xenomorph is depicted being born from Baraka, creating a new, and exclusively unique variation of the Alien.

Powers and abilities
Xenomorphs are structurally superior to most other lifeforms. They possess great strength, speed and agility, the ability to stick to walls, a cunning intelligence, and most notably, highly corrosive blood, giving them an incredible defence mechanism. These traits have led many to identify the species as the "perfect organism." Because of this, many humans have attempted to try to control and use them for their own personal gain, usually for military weapons. For example, the Cobblepot Industries used clone Xenomorphs to erase half of humanity by the orders of the Dixmor Project.

The Tarkatan-born Xenomorph retains all of these traits as well as a new feature; segmented blades located in sheathe-like appendages on its forearms. These blades are used to rip, slice and impale targets.

As with every Xenomorph, this specimen also has an "inner jaw" in which it can shoot out of his mouth at great speeds, capable of effortlessly punching a hole though tissue and bone.

Trivia

 * As the Xenomorph has a highly corrosive blood, his opponent will die in a finisher that involves ingesting its blood, plunging body parts into its body, having its blood splash all over them, biting them, or any contact with the Xenomorph's blood.
 * A Shokan Xenomorph can be seen during Alien's ending, with Goro seen hanging behind the Alien. There is also a pair of Aliens that appear to have been birthed from Ferra & Torr.
 * When the Predator performs his Skinned Alive brutality on Alien, he will be decapitated instead due to its exoskeleton.
 * When the Xenomorph wins a match without a fatality or a brutality, he walks up to the screen, which then goes black. The opponent is shown trapped and bound in an Alien nest, grunting in pain before a newly-born Xenomorph bursts through their chest, killing them. This makes the Alien one of four characters in Mortal Kombat who will always kill the opponent after a match, the others being Corrupted Shinnok, Stryker and the Predator.
 * Depending on the opponent, the chestburster that appears post-match or in the Alien Baby brutality may take on a different appearance from his standard form depending on the opponent.