Type: Endoparasitoid extraterrestrial species
Species: Xenomorph XX121
Also known as: Xenomorph Egg
First Appearance. Alien 1979
Appears in: Alien (1979), Aliens (1986), Alien 3 (1992), Alien 4 (1997), Alien vs. Predator (2004), AVPR: Requiem (2007)
The Ovomorph, 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.
Xenomorph Eggs by themselves are seemingly inert, although they apparently posses some ability to “sense” or otherwise detect when a potential host creature approaches, at which point four “petals” at the top of the Egg will open up and the Facehugger within will launch itself out at the nearby victim.
Ovomorphs are produced by Queens in their Egg sac and then laid through the trunk-like ovipositor at the rear of the sac. 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. Far more than simply a hollow vessel in which the Facehugger resides, the Ovomorph is in fact a complete organism in its own right. 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. Likewise, the tough outer skin is difficult to cut through, and doing so will cause acid to spray defensively from the incision.
An Egg usually contains only a single Facehugger, but some have been seen to contain as many as four. 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. It appears that a hot, humid environment is preferable for optimum incubation. 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. 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.
Detecting the Host
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. 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. 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.
Once a host is detected, the Egg releases a catalyst that unlocks the acids bonded into the chemical salts, releasing the energy being stored. 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. 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. 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.
Over time, if not disturbed, Eggs will develop several tendril-like roots that spread from their base. 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. 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).
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. 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.
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.