The Planet 4 Xenomorphs, also known as Protomorphs, 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 8.


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.


After Oram shot down a Neomorph, an enraged David tricked the former into following him to his workshop where he has been experimenting on the pathogen to create the perfect organism. David brought the captain further down revealing a chamber filled with large eggs. Oram didn't realize how they functioned until it was too late as a Facehugger leapt out of its egg and viciously latched onto his face.

Some time later, Oram awakened and had a brief discussion with David about their beliefs. Seconds later, a Chestburster ripped its way out of his chest, killing him while David looked on and smiled at the newly born Xenomorph.

Sergeant Lopé and Cole discovered the workshop in search of Oram. Cole found not only Oram's body but also another Facehugger. It attacked Cole and latched on to his gun. Cole managed to throw it off and shot at it, though it dodged his gunfire and instead ran toward Lopé. As the two tried to locate the creature, it attacked Lopé. As he struggled to get it off his face, Cole ran over and used a knife to cut it off Lopé's face, the resulting acidic blood burning Lopé's cheek. As Cole tried to bandage his face, Lopé noticed the Xenomorph looking down at them from an overhead shaft. Panicking, Lopé got up and ran as it immediately dropped down and landed on Cole, pinning him down and killing him while Lopé escaped.


The Xenomorph soon pursued the crew of the Covenant and discovered them attempting to escaped on a ship. Although it managed to get on board and endured many injuries that would normally prove fatal, it was soon killed by the crew members.

The crew took Lopé to a medical ward. MU-TH-UR contacted Daniels and informed her about an unidentified lifeform present on the ship. Daniels and Tennessee headed to the medical ward and found Lopé dead with his chest burst open, revealing that the Facehugger from earlier had managed to impregnate him.

The Xenomorph wandered around its surroundings and ambushed Ricks and Upworth while showered together, killing Ricks via headbite before murdering Upworth. The Xenomorph was lead to the Terraforming Equipment Bay where the two remaining members were. The alien chased after Daniels who intended it to do so and trapped it inside one of the vehicles. Daniels ordered for the Terraforming Equipment Bay doors to open sending the vehicles into space. However, the Xenomorph broke out and attempted to perform one more feat to return to the ship. Another vehicle finally impaled it and sent it flying out of the Covenant. The Xenomorph was then burned up upon re-entering Planet 4's atmosphere, killing it.


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 spines are noticeably different, being smaller and narrower. This Xenomorph variant also has a thinner, sleeker tail that ends with a small barb or stinger.

Covenant trailer egg (3)
Covenant trailer egg (2)

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.[1][2] 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".[3]

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.

Overall its growth rate is incredibly fast, as it can be seen visibly growing after only just emerging from its host. Not long after this, it is next seen as a fully mature adult.

The Planet 4 Xenomorph can see almost as clearly and detailed as humans, though they have "floaters" througout their vision.


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.

Life Cycle

For the life-cycle of Xenomorph XX121 see:Xenomorph life cycle


Main article: Ovomorph (Planet 4)

Like all members of the species Xenomorph XX121, the Xenomorphs on Planet 4 have a complex and parasitical life-cycle that requires a host. The process itself is actually completely identical with the creature having its beginnings in an Egg of similar shape to its cousins, though with notable differences in shape.


Main article: Facehugger (Planet 4)

Once the egg opens, a Facehugger will emerge, attach itself to the face of a host, and immediately implant an embryo, with seemingly even a brief moment of contact being able to ensure impregnation. Though the removal of the Facehugger is less difficult compared to the mainstream variant, as it has less potent acid blood, the Planet 4 Facehugger is able to counteract these setbacks by seemingly being able implant a host within seconds of attachment.


The Chestburster uses its shape to burst its way out of its host, and once it emerges, it undergoes almost immediate transformation. Due to this species accelerated growth, the Chestburster itself seems to be born almost fully developed, similar to the Chestburster that emerged from an animal on Fury 161.


  • According to Ridley Scott's director's commentary, the Planet 4 variant of the Xenomorph is able to regenerate from would-be fatal injuries like being crushed and dismembered, making it virtually indestructible.
  • Its design was based on that of an écorché, while its movements were based on those of a praying mantis and a baboon.[4][5]
  • This Xenomorph has a human skull underneath its smooth dome, something the original Xenomorph (from Alien) also featured.
  • The exact origins and nature of this Xenomorph have been widely debated amongst fans, with some believing David is responsible for the Xenomorph XX121 species, while others believe he merely recreated something that the Engineers created. The reason for this debate is due to evidence of the existence of a Xenomorph-like species, depicted in a mural shown inside the Engineer Ship explored by the Prometheus crew. It is still unclear if David saw the mural due to the fact that in the film it is never specified, therefore creating a debate between some fans on whether this had any influence in David's experiments or not.
    • In addition to the belief that David is responsible, some fans have nicknamed the Covenant variant a Protomorph, believing that it is the precursor or progenitor to the original species.
    • In the novelization and early drafts of the script, the Xenomorph XX121 species was created by the Engineers, and David's Xenomorph variant was created in an attempt to replicate them. The final film lacks this revelation, with comments by Ridley Scott indicating that the decision was made late in development to have David be the sole creator.
  • In the novelization, the Xenomorph is described as possessing a biomechanical mesoskeleton, but in the film itself, the Xenomorph lacks biomechanical features, stated in interviews to have been a deliberate design decision. 
  • The Planet 4 variant appears to have the similar life-cycle speed to those in Alien vs. Predator. It also appears that the parasite stage is capable of implanting a host within seconds of attachment. Both have caused criticism amongst fans.
  • The Planet 4 Xenomorph's motion capture was provided by Javier Botet, a Spanish actor with Marfan Syndrome who is mostly known for his roles in REC (2007) and Mama (2013).[6]
  • There are notable differences between the film Xenomorph and the NECA figure: the NECA figure has shoulder tubes and the tubes on the back of the figure are more upright. The film Xenomorph lacks shoulder tubes and the back tubes are more separated and bent over. That's because NECA has been provided with concept art by Colin Shulver.




Concept art



  1. Dan O'Bannon, Ronald Shusett (writers), Ridley Scott (director). Alien (1979), 20th Century Fox [DVD].
  2. Paul W. S. Anderson (writer and director). Alien vs. Predator (2004), 20th Century Fox [DVD].
  3. Tim Bogenn. Aliens vs. Predator: Bradygames Official Strategy Guide, p. 25 (2010), DK/BradyGames.
  4. "'Alien: Covenant' VFX Team Hatches New Neomorph, Xenomorphs". Hollywood Reporter (21 May 2017).
  5. "‘Alien: Covenant’: How the VFX Team Engineered Those Terrifying Xenomorph and Neomorph Creatures". Indie Wire (24 May 2017).
  6. "Bloody Disgusting - Javier Botet Provided the Xenomorph Motion Capture for ‘Alien: Covenant’" (2017/09/11).
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