The Praetomorph,[1] also known as the Planet 4 Xenomorph, was a variant of the species Xenomorph XX121 that attacked the crew of the USCSS Covenant. The species originated on Planet 4 as a result of genetic experimentation carried out by David 8.

The Praetomorph further evolves into a Stalker.


The Praetomorph 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 leaped out of its egg and viciously latched onto his face.

Sometime 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 Praetomorph.

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 Praetomorph 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 Praetomorph soon pursued the crew of the Covenant and discovered them attempting to escape 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 Praetomorph wandered around its surroundings and ambushed Ricks and Upworth while showered together, killing Ricks via headbite before murdering Upworth. The Praetomorph 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 the Terraforming Equipment Bay doors to open sending the vehicles into space. However, the Praetomorph 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 Praetomorph 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 Praetomorph 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.[2][3] 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".[4]

The most unique aspects of the variant are its incredible resilience and determination. When onboard 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 Praetomorph can see almost as clearly and detailed as humans, though they have "floaters" throughout their vision.


The Praetomorph 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 Praetomorph got itself killed by attacking the moving crane claw by jumping into it, which resulted in it being crushed to death and the second Praetomorph attacked the video feed of David.

Life Cycle

See: Xenomorph life cycle


Main article: Ovomorph (Planet 4)

Like all members of the species Xenomorph XX121, the Praetomorph has 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 to 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 an 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.


  • The name Praetomorph was developed by the creators of Alien: The Roleplaying Game from the term "Protomorph" (previously used during the conceptual stage for the Deacon in Prometheus[5]) combined with the prefix "prae", taken from the Plagiarus praepotens mutagen described in the novel Alien: The Cold Forge.
  • According to Ridley Scott's director's commentary, the Praetomorph 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.[6][7]
  • The Praetomorph has a human skull underneath its smooth dome, something the original Xenomorph (from Alien) also featured.
  • The exact origins and nature of the Praetomorph 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 Praetomorph 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 Praetomorph lacks biomechanical features, stated in interviews to have been a deliberate design decision. 
  • The Planet 4 variant appears to have a 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 Praetomorph'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).[8]
  • There are notable differences between the film Praetomorph and the NECA figure: the NECA figure has shoulder tubes and the tubes on the back of the figure are more upright. The film Praetomorph 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.
  • One of the Minimates figures of the Praetomorph is named the "Goran Xenomorph", this is a reference to the actor who portrayed the Praetomorph, Goran D. Kleut.




Concept art



  1. Andrew E. C. Gaska. Alien: The Roleplaying Game, p. 284 (2019), Free League Publishing.
  2. Dan O'Bannon, Ronald Shusett (writers), Ridley Scott (director). Alien (1979), 20th Century Fox [DVD].
  3. Paul W. S. Anderson (writer and director). Alien vs. Predator (2004), 20th Century Fox [DVD].
  4. Tim Bogenn. Aliens vs. Predator: Bradygames Official Strategy Guide, p. 25 (2010), DK/BradyGames.
  5. "Studio Yutani - FYI the Deacon is the Protomorph". Retrieved on 2019-12-02.
  6. "'Alien: Covenant' VFX Team Hatches New Neomorph, Xenomorphs". Hollywood Reporter (21 May 2017).
  7. "‘Alien: Covenant’: How the VFX Team Engineered Those Terrifying Xenomorph and Neomorph Creatures". Indie Wire (24 May 2017).
  8. "Bloody Disgusting - Javier Botet Provided the Xenomorph Motion Capture for ‘Alien: Covenant’" (2017/09/11).
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