PLANET 4 XENOMORPH (ALIEN COVENANT)
A variant of the species known as Xenomorph XX121
The Planet 4 Xenomorphs were a variant of the species known as Xenomorph XX121 that attacked the crew of the USCSS Covenant. The species originated on Planet 4 as result of experimentation by David.
The Covenant variant of Xenomorph XX121 was created by the android David 8’s experiments using the Chemical A0-3959X.91 – 15 pathogen as a catalyst on tissue samples harvested from Elizabeth Shaw, deceased Engineers, and Neomorphs spawned from the native species of Planet 4. Over the course of a decade, David continued to perfect his designs until he created the first Ovomorphs, which contained Facehuggers that implanted two members of the Covenant’s crew, who later birthed the first versions of the Xenomorph on Planet 4. After hijacking the USCSS Covenant, David transmitted the records of his experiments to the Weyland-Yutani Corporation, expressing the intent of continuing his experiments using the settlers and surviving crew, and creating a Queen that would change everything.
While virtually identical to Xenomorph XX121, this version possesses 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 Dorsal Tubes are noticeably different, being smaller and narrower. This Xenomorph variant also has a thinner, sleeker tail that ends with a small barb or stinger.
The differences in the Drone extend to its Chestburster form as well as the Facehugger to a lesser extent. Other than these differences, the Xenomorph greatly resembles the Xenomorphs that had come from the Derelict on LV-426.
Like Xenomorph XX121, this variant possesses an inner pharyngeal jaw. This appendage is capable of shooting from their mouth like a piston 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. When on board on the ship Tennessee was flying, one received a full blast from one of the ship’s thrusters but it continued its hunt despite being bathed in flames. Another proved its relentlessness by breaking out of the vehicle Daniels trapped it in and ran across the falling vehicles to get back to the Covenant.
The Planet 4 strain of Xenomorph possesses more or less the same basic intelligence but seems to be unable to differentiate between living or inorganic objects when they are moving, as the first Xenomorph got itself killed by attacking the moving crane claw by jumping into it, which resulted in it being crushed to death and the second Xenomorph attacked the video feed of David.