"It's full of leathery objects, like... eggs or something."
Kane, regarding the Eggs inside the derelict (from Alien)

The Ovomorph,[2][3][4] known colloquially as the Egg, is an egg-like capsule containing a Facehugger, generally considered to be the first stage in the life cycle of the species Xenomorph XX121. They are produced and laid by a Queen but can also be produced by the inducement of a process of metamorphosis on a captured victim which then changes into a viable ovomorph.

Xenomorph Eggs by themselves are seemingly inert and are often dismissed as nothing more than lifeless vessels simply designed to contain the Facehugger. However, study has shown that they are in fact complicated organisms in their own right and that they exist in a symbiotic relationship with the Facehugger they contain.[5] They notably possess the ability to "sense" or otherwise detect when a potential host creature approaches, at which point four "petals" at the top of the Egg open up and the Facehugger within launches itself at the nearby victim.


Ovomorphs are produced by Queens in their ovipositor and then laid through the trunk-like appendage at the rear of the ovipositor; each Egg contains a fully-formed Facehugger the moment it is produced.[1] Eggs stand around two and a half feet tall and are typically brown-black and leathery in appearance, although older specimens have been seen to exhibit a drier, grey-white exterior.[6] Far more than simply a hollow vessel in which the Facehugger resides, the Ovomorph is in fact a complete organism in its own right.[5] The capsule itself is incredibly durable – experiments have shown it is possible to drop one from the top of a tall building at Earth's gravity, and it will bounce upon impact with the ground without rupturing or causing any harm to the Facehugger within; even at three times Earth's gravity, the Egg will maintain its integrity.[7] Likewise, the tough outer skin is difficult to cut through, and doing so will cause acid to spray defensively from the incision.[7]

An Egg usually contains only a single Facehugger, but some have been seen to contain as many as four.[8] Other than a Facehugger, Eggs also contain a mass of flesh and stringy ligaments, the purpose of which is unknown, although it seems likely this material plays some part in sustaining the Facehugger. An Egg and its occupant typically weigh around 60 pounds.[9] It appears that a hot, humid environment is preferable for optimum incubation.[10] Eggs can apparently sustain the Facehuggers they contain for hundreds or even thousands of years with no external nutrients or assistance – specimens discovered by the crew of the Nostromo had apparently been dormant for hundreds if not thousands of years. The key to the Egg's longevity is the manner in which it locks much of its energy-generating acid blood into relatively stable salts that decay very slowly over long periods of time.[11] However, it seems that, despite their longevity, Eggs will eventually expire over time; during Kane's exploration of the derelict on LV-426, he fell and directly struck an Egg, yet it did not open or respond in any way. Similarly, During the Anesidora crew's later exploration of the same site, three crewmembers were freely exploring the cargo hold in close proximity to the Eggs, yet only one opened and unleashed its Facehugger. This could indicate many of the Eggs in the derelict had died.

It is not known if an empty Egg will create more Facehuggers, although the fact that spent Eggs are usually discovered hollow and empty seems to preclude this.[12]

Detecting a host[]


A Xenomorph Egg opened, with the interior visible.

Dissection of Eggs has shown that they possess a rudimentary central nervous system at their base, linked to the network of thermo- and pressure-sensitive veins that run across the outer surface.[11] These allow the Egg to "perceive" when a host is detected nearby. It has also been proposed that the Egg's skin may contain some form of sensory organ that allows it to "taste" a host at a distance, similar to a snake's tongue.[2] Whatever the mechanism, it is thought that the detection process is sensitive enough to allow an Egg to orient the Facehugger within so that it is pointed at the host, ready to subdue it, and that the Egg can even sense whether a potential host is of a viable size.[2]

Once a host is detected, the Egg releases a catalyst that unlocks the acids bonded into the chemical salts, releasing the energy being stored.[11] These free acids are then transferred to the Facehugger, which only becomes "live" at this point – thus explaining why the Facehugger itself displays no life-signs prior to its emergence.[5] Essentially, the Ovomorph transfers its remaining bio-electrical potential to the Facehugger, sacrificing itself so that the Facehugger can become sufficiently active to attack the host on short notice.[11] Immediately prior to release, the top of the Egg splits open in four sections that peel back like the petals of a flower, allowing the Facehugger to leap out. Tests performed by Venture Corporation scientists at the V-22 facility showed that an Ovomorph is capable of resealing itself if the lifeform it detected is not suitable for Chestburster implantation.[13]

Ripley and Newt in Hive

Ellen Ripley and Newt surrounded by Eggs with roots.

Over time, if not disturbed, Eggs will develop several tendril-like roots that spread from their base.[12][14] It is possible that these roots are for nutrient absorption, similar to plant organisms, to help the Egg sustain itself and the Facehugger within until a potential host appears, although the discovery of viable Eggs in nutrient-deficient environments seems to cast doubt on this theory.[6] Another suggested purpose for the tendrils is that they are used for communication between Eggs, like the synapses in brain cells, as they have commonly been seen in large clusters of Eggs. The connections may allow Eggs to inform each other of host approach, or even act as a mechanism for detecting hosts directly (whether through physical contact, or thermal or bio-electric means).[2]

Reactive mist[]

The Eggs found aboard the derelict on Acheron were covered by a thin layer of bluish mist that reacted when broken. It was also seen to interfere with radio communications, although it is unlikely this is its primary or intended purpose.[6] It is not clear whether this mist was put in place artificially by the Engineers, or whether it was generated by the Eggs themselves. While the mist has never been seen again in the Alien film franchise, it has been seen in several of the video games based on the series; some of these appearances seem to imply it is produced by the Eggs themselves.[15]

The effect and relationship between the mist and the Eggs is not clear. It is possible that the mist is a security mechanism implemented by the Engineers, subduing the Eggs and their contents in a similar manner to how smoke affects worker honey bees, thereby rendering them safe to transport. However, the mist also appears to react when broken and awaken the Facehuggers within the Eggs, alerting them to the presence of a host, which would seem to contradict the security feature theory.


Breeding Eggs[]

Main article: Breeding Egg

According to Dr. Orona's Theory of Alien Propagation, Queens, when cued by instinct, lay special Breeding Eggs that hatch special spotted, spined Facehuggers which are capable of implanting juvenile Queens in their host.

Hyperfertile Eggs[]


Normal and Swollen Egg

Hyperfertile Eggs are an evolution to the typical Ovomorph that can quickly grow the Hive's numbers. Instead of one Facehugger to an Egg, these Eggs can hold anywhere from two to four, inversely proportional to how well the Hive is doing – if low in number, Eggs will hold up to four Facehuggers, but if the Hive is doing well, only two or sometimes just one.

Praetorian Eggs of this variety will hold one Praetorian Facehugger alongside one or several normal Facehuggers.

Praetorian Eggs[]


Praetorian Egg

Praetorian Eggs are a variation of the normal Egg that costs more resources and effort to create than the standard egg. Different from a normal Egg, Praetorian Eggs are thicker and affect a more greenish coloration. They molt from normal Eggs, the Facehugger within changing as they do, becoming a Praetorian Facehugger. Such Facehuggers always give rise to a Praetorian, regardless of host.

Praetorian Facehuggers are one possible route to creating a Queen, along with the Ravager and Carrier castes.

Mutant Variants[]

Pink Ovomorph

A Pink Ovomorph containing a Facehugger that spawned a Goreburster

Pink Ovomorph[]

Main article: Goreburster

It was an irregularly coloured pink ovomorph that hatched the mutant Chestburster known as the Bodyburster which resembles a large black Chestburster. The pink egg was found amongst an ordinary clutch, though the origins of such eggs are unknown. During gestation the Goreburster's host will develop a series of flu-like symptoms, such as fatigue, nausea, and bloating (the latter most likely due to the creature's sheer size). It emerges much like a normal chestburster, albeit much larger and more aggressive. One Goreburster egg was smuggled to the pleasure planet Celeste by Weyland-Yutani employees. The resulting hatchling, after escaping its human host, caused chaos on the planet by biting people and injecting a poisonous substance that caused the victims to explode.

Non-canon Depictions[]

Alien 2: On Earth[]

Main article: Alien 2: On Earth

The Xenomorph Eggs in the non-canon film Alien 2: On Earth are almost completely different from the Eggs in the rest of the franchise. The Eggs in this film look like rocks, rather than the leathery egg-shaped objects seen in the official series and its related media. Like other Xenomorph Eggs, these eggs open at the top and a Xenomorph Facehugger launches out at the victim. Rather than green or gray, these eggs are blue.

Mortal Kombat X[]

The Ovomorph egg appears in the 2015 Fighting game Mortal Kombat X as part of the Tarkatan Xenomorph's move set.

Behind the Scenes[]


H. R. Giger initially designed the egg with a much more obviously vaginal appearance, complete with an "inner and outer vulva".[16] The producers complained that Catholic countries would ban the film if the allusion was too strong, so Giger doubled the lobes to four, so that, in his words, "seen from above, they would form the cross that people in Catholic countries are so fond of looking at."[16]


For Alien, a total of 130 Eggs were built for the Egg chamber scene, constructed from plaster, with a single "hero Egg" that featured a rubber top that was articulated with hydraulics and capable of opening.[17] The interior of the hero Egg seen was composed of "Nottingham lace", which is the lining of a cow's stomach. The movement within the Egg as Kane inspects it was generated by director Ridley Scott himself, who inserted his hands (in rubber washing-up gloves) into the model and ruffled his fingers.[18] In the first film, the quick shot of the Facehugger erupting from the egg was done with sheep's intestine, propelled by a pressurized air.[18] The Eggs in the early films had just four points of articulation; however, by Alien Resurrection the entire Egg was made to ripple as it opened with 25 points of articulation that required 7 puppeteers to operate.[19]


The iconic image of the Egg, made from a decorated chicken's egg.

Initial test shots filmed for Alien used decorated chicken eggs to represent the Alien spores, and this footage was used in early teaser trailers for the film. One of these eggs was also used as the primary image for the film's advertising poster (and on many subsequent home video releases and other related media), and thus became a lasting image for the series as a whole, despite being visibly different from the Xenomorph Eggs that actually appear in the films.[20]

In the novelization of Alien, the Egg is somewhat different to the versions depicted in the movies. In its dormant state, the Egg is smooth and opaque, but just prior to the Facehugger emerging it becomes transparent and its surface becomes lumpy and rough.[21] Notably, it has no opening whatsoever, and the Facehugger within simply explodes forcefully through the top when it emerges.[22]


Main article: Eggmorphing

While Eggs are ostensibly created by Queens, Alien originally showed that any adult Xenomorph was capable of creating new Eggs from the bodies of its victims, alive or dead; this process has been dubbed "Eggmorphing". While the sequence showing this was removed from the film before its release, it was later reinstated in the Director's Cut, released in 2003.


  1. 1.0 1.1 1.2 1.3 Weyland-Yutani Archives (2008), 20th Century Fox [Blu-ray]
  2. 2.0 2.1 2.2 2.3 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 150 (2012), Titan Books.
  3. Aliens: Colonial Marines, Microsoft Windows, PlayStation 3, Xbox 360 version, Gearbox Software, 2013.
  4. Alien: Bloodlines Issue 5
  5. 5.0 5.1 5.2 Dave Hughes, Lee Brimmicombe-Wood. Aliens, Vol. 2 #17, p. 42 (1993), Dark Horse International.
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  8. Aliens versus Predator: Extinction, EA Games, 2003.
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  10. S. D. Perry. Alien: The Weyland-Yutani Report, p. 13 (2014), Insight Editions.
  11. 11.0 11.1 11.2 11.3 Dave Hughes, Lee Brimmicombe-Wood. Aliens, Vol. 2 #17, p. 43 (1993), Dark Horse International.
  12. 12.0 12.1 James Cameron (writer and director). Aliens (1986), 20th Century Fox [DVD].
  13. Tim Waggoner. Alien: Prototype, p. 40 (2019), Titan Books.
  14. Joss Whedon (writer), Jean-Pierre Jeunet (director). Alien Resurrection (1997), 20th Century Fox [DVD].
  15. Aliens vs. Predator, Microsoft Windows version, Rebellion, 2010.
  16. 16.0 16.1 H. R. Giger. Giger's Alien, p. 46 (1979), Morpheus International.
  17. John Hurt, Dan O'Bannon, Ronald Shusett, David Giler, Sigourney WeaverThe Alien Saga (2002), Prometheus Entertainment [DVD].
  18. 18.0 18.1 Ridley Scott, Dan O'Bannon, Ronald Shusett, David Giler, Veronica Cartwright, Ivor PowellThe Beast Within: Making Alien (2003), 20th Century Fox [DVD].
  19. Jean-Pierre Jeunet, Sylvain Despretz, Darius Khondji, Pitof, Alec Gillis, Tom Woodruff, Jr.One Step Beyond: Making Alien Resurrection (2003), 20th Century Fox [DVD].
  20. David McIntee. Beautiful Monsters: The Unofficial and Unauthorised Guide to the Alien and Predator Films, p. 34 (2005), Telos Publishing.
  21. Alan Dean Foster. Alien, p. 99 (2014), Titan Books.
  22. Alan Dean Foster. Alien, p. 100 (2014), Titan Books.