PETI-88 is a very small extraterrestrial life form. It bears an appearance and lifestyle similar to Earth’s nematode worms, phylum Nematoda. PETI-88 was measured at 3mm in length, with a thin and flat body. It bears microscopic sensory bristles all over the body, with larger “grasping” bristles on one end of the body. Sharp retractable spurs exist on the other end, which can be used to burrow into tissue and otherwise navigate. The body is covered in small linear grooves, which are more visible when the body of PETI-88 is contracted. PETI-88 has an unusually complex and fragile nervous system, which allows for complex thought and communication. PETI-88 has no eyes or true limbs. PETI-88 has no apparent mouth or anal cavity, likely absorbing nutrients and removing waste through its skin. It has a carnivorous diet, but will not feed off its own host tissues unless necessary for survival.

PETI-88 has a necessarily parasitic lifestyle. They are incredibly complex endoparasites that reside in the brain and affect the entire body. They are transmitted primarily through blood, but can enter the body by being ingested or even burrowing directly into flesh. It can move incredibly fast in even foreign bodies, and locates the brain or central nervous system via fine-tuned electroreceptors. Effects of PETI-88 were tested in mice and rhesus macaques, as well as artificially produced human brain segments.

PETI-88 was recovered from UAP-009, in a damaged robotic case. It remained nestled in a semi-artificial false brain. After being recovered from the false brain, PETI-88 was to be placed in a 70% ethanol preservation solution, but when movement was detected was quickly relocated to a chunk of the origin brain. PETI-88 should remain stored in a small-sized secure containment unit within a polypropylene tupperware container, and kept with its false host brain. Transferral of PETI-88 to other hosts is permitted under special circumstances, and host transmission must only be done temporarily and securely before PETI-88 must return to its origin brain. PETI-88 appears to have high intelligence and the ability for complex thought, and may even be considered sapient. Studies with artificially produced brain segments linked to a computer to allow PETI-88 language-based communication capabilities were done, however PETI-88 was not able to produce anything comprehensible to humans.

The speed at which PETI-88 becomes apparent in its hosts varies from mere seconds to several hours. Initial signs of infection are mild discomfort in the host. 1-2 days post infection, the tissue of the host will gain dark bruise-like patches. An increase in appetite will be seen, and the host may seem dazed. Sleep periods increase significantly. PETI-88 gains control over many motor functions, notably in the limbs. By 3-5 days, all of the host’s interior tissue will change to a dark purple colour. This does not change the host’s external appearance, and is only visible through damage or the interior of the mouth. Appetite further increases, along with aggression. The host may begin refusing to eat non-meat products. PETI-88’s movements will become more coordinated. At 4-11 days, the host’s teeth will change form, becoming broader, tougher, and pointed. Exhaustion will wear off around this time. The parasite will erupt a stalk from the host’s head, which bears a complex eye structure. This stalk is permanent and controlled via the parasite, and is the most obvious sign of a complex infection. Severing the stalk will not harm the parasite, and it will regrow. Anywhere from 6-14 days onward, the parasite gains the ability to rapidly mutate tissue in the host’s body in complex manners. These mutations are only temporary, and the host can quickly return to it’s original form. This aids PETI-88 in feeding, allowing it to mutate any manner of weapons. It also allows PETI-88 to rearrange segments of the body as it sees fit, or to heal injuries of the host. Mutated parts are made of organic tissue and mutated flesh is a dark purple colour. Mutated parts are controlled by PETI-88 independently of the host. The host remains fully conscious and sentient, even whilst PETI-88 takes control of body segments. Mutations cause no apparent pain to the host, whilst external injuries still do. Mutations can be extremely complex, but are somewhat limited by PETI-88’s energy.