Xenomorph Ovomorph - Egg

Species

• Xenomorph XX121

Height

• 2ft - 2 1/2ft

Diameter

• 1ft

Weight

• 56lbs

Skin Color

• Black-brown, black-green

The Ovomorph, known colloquially as the Egg, is an egg-like capsule containing a Xenomorph Facehugger, generally considered to be the first stage in the life cycle of the species Xenomorph XX121. They are produced and laid by a Xenomorph 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 Xenomorph 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 Xenomorph Facehugger they contain. 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 Xenomorph Facehugger within launches itself at the nearby victim.

Characteristics
Ovomorphs are produced by Xenomorph Queens in their ovipositor and then laid through the trunk-like appendage at the rear of the ovipositor; each Egg contains a fully-formed Xenomorph Facehugger the moment it is produced. 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 Xenomorph 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 Xenomorph 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 Xenomorph Facehugger, but some have been seen to contain as many as four. Other than a Xenomorph 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 Xenomorph 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 Xenomorph Facehugger they contain for hundreds or even thousands of years with no external nutrients or assistance. 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. However, it seems that, despite their longevity, Eggs will eventually expire over time. It is not known if an empty Egg will create more Xenomorph Facehugger, although the fact that spent Eggs are usually discovered hollow and empty seems to preclude this.
Detecting a 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 Xenomorph 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 Xenomorph Facehugger, which only becomes "live" at this point – thus explaining why the Xenomorph Facehugger itself displays no life-signs prior to its emergence. Essentially, the Ovomorph transfers its remaining bio-electrical potential to the Xenomorph Facehugger, sacrificing itself so that the Xenomorph 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 Xenomorph 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 Xenomorph 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).
Reactive mist
The Eggs found aboard many ships 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. The effect and relationship between the mist and the Eggs is not clear. The mist also appears to react when broken and awaken the Xenomorph Facehugger within the Eggs, alerting them to the presence of a host.