Xenochimera

Home planet: Not known

Home system: Not known

An extraterrestrial colony organism, xenochimera are unusual in that they have no real defining physiology of their own - effectively, xenochimera mimic other beings, or parts of other beings, by consuming them and mutating their own cellular structure to imitate whatever evolutionary advantages they may find.

The origins of xenochimera are presently unknown - xenochimera biomass has been found frozen in space, buried in asteroids, and in rare cases mistaken for fossils in xenoarchaeological digs, with at least one known example of such a creature making planetfall in a meteorite - although it could be better described as a "seed" than a "creature" at that point.

On the cellular level, these creatures are composed of a hive of microscopic organisms - these form the basis of the majority of their bodily systems. When they feed on another being, effectively these organisms will consume the prey like a flesh-eating bacteria, rather than the more typical acidic digestion used by many other species (note: that doesn't mean that a particular example of the species hasn't found that a traditional stomach is a desirable evolutionary trait to copy) and, once having consumed enough, the cells will split, possibly mutating to mimic that which was eaten, and assimilate themselves into the rest of the hive. Individual chimera cells are capable of rudimentary communication with their neighbours, forming a sort of primitive neural network, but are not capable of anything resembling intelligence beyond primitive survival instinct. Effectively, the default state of a xenochimera is an order of intelligence on a par with an ant colony - not an individual ant but the colony itself, driven by little more than to survive at all costs.

That is, unless they manage to assimilate and mimic something with a complex nervous system. At this point, provided that the hive successfully copies it, they can find themselves awakening to a greater degree of understanding than they have ever managed before - however, they are still the colony when all is said and done, and pressing survival needs will override whatever refined thoughts they may hold in their heads, leaving them generally prone to panic and fight-or-flight responses in extremely stressful situations, when injured or damaged, or driven to feed when hungry. The most common term used to describe a xenochimera that has reverted to primitive instinct in this manner is "feral".

Xenochimera do not reproduce sexually. Genetic diversity is attained through their diet, making the evolutionary advantages of mating a somewhat moot point. Typically, their digestive, immune, and reproductive systems are all one and the same - individual cells within the colony locate foreign cellular material, consume it, and then split into more chimera cells. The process by which new colonies are formed is not wholly understood, though exposing a laboratory mouse to a suitably large dose of chimera cells has resulted in the mouse being consumed and the resulting cellular mass forming into a proto-mouse copy. Either way, typically reproductive organs are absent from xenochimera colonies as they serve no useful purpose to them.

In most cases medical treatment is fairly standard as the colonies are mimicking the basic physiology of other species - if they are leaking fluids, then bandage them as normal. If they are poisoned, administer the usual pharmacy treatments. If they have suffered organ damage, provide surgical treatment. However, it should be noted that their bizarre genetic structure is completely incomprehensible to all available cloning technology. They are rather hardy creatures, though, and even if a colony is damaged to the extent that it appears "dead", as long as there is still some viable material present they can likely be revived, in a fashion, by injecting the body with a concentrated nutrient solution to prompt whatever remaining living cells are present to come out of hibernation and go about regrowing themselves. The process is not pretty, as the colony will effectively cannibalise any unviable biomass and grow a new body from scratch. This process can take anything from minutes to weeks, depending on the extent of the damage, and is extremely draining on the colony's resources - they will most likely be in a feral state when they emerge, and will almost certainly be suffering from neural degradation as a result of the trauma. Regrowing and repairing nervous tissue is extremely troublesome for them, and a colony that has suffered neural damage will often require an extensive period of recuperation and hibernation to come even close to fixing it themselves. Or they might just eat someone's head and skip that part.

Typically, a colony will do whatever it can to avoid the need for such drastic measures - extremely stressful situations will prompt them to adapt on the fly in an attempt to minimise damage in whatever way they can - as one enterprising tajara scientist found out, even to the point of mimicking a host's own cells and hiding within their body. (the scientist suffered no ill-effects, though was quoted as saying "She will find otherr mice outside the lab to eat next time.")

Xenochimeras can be extremely voracious, especially when in a feral state due to hunger. While in this state, they will be unable to use most objects; primarily guns and other "advanced" items. A feral xenochimera is not always identifiable at first glance (even in their more lucid moments, they have a tendency to display instinctive behaviour, sometimes even the instincts of whatever creatures they are composed of), but can usually be spotted upon closer examination. The only way to get a feral xenochimera out of this feral state is to remove whatever source of stress is driving them into a feral state in the first place - if they are hungry, feed them - and be aware that the majority are obligate carnivores, and the closer the meat is to being alive, the better. If they are panicking, remove whatever is scaring them. If they are injured, let them heal. An entire crew descending on them to rubberneck will often elicit the same response that one would get from any cornered and frightened animal.

If there are offshoots of the species as a whole, nobody has yet managed to identify them. Due to the wide range of diversity within the species, even if a specimen were to be obtained, it would be near-impossible to conclusively show that they were a different sub-species and not just another colony. For instance, it has been suggested that another species, dubbed "endochimera" is a genetic offshoot, while others believe they evolved independently and are another species entirely despite the superficial similarities.

Oh, and there's still no such thing as changelings.