Species XX121

Species XX121 is a species of highly aggressive, parasitic organisms of unknown origin. Little to nothing is known about these organisms, including their life cycle outside of the initial phases, structure of their society, or if they are of natural or artificial origin. XX121 is notable for its extreme hostility to seemingly all sentient life, as well as its method of reproduction via which an embryo is forcefully implanted into a host and depending of the species and potentially other factors such as augmentation will birth a different variant of the species.
==History==
===Ancient History and Speculation on Origins=== 
As of 2558, records of XX121’s existence in ancient history are sparse, but present. A recent recovery of Forerunner records makes mention of creatures similar enough in description to XX121 for ONI’s experts to conclude they were the same species. These records state that XX121 was deployed as means of area denial and as shock troops by another, even more during a with the .
It should be noted however, that the descriptions and associated imagery is not a perfect match for the currently encountered specimen, but were similar enough in appearance and behavior for it to be concluded they were indeed the same species. It is speculated these differences are a result of a different species than human or canine playing the role of host, but could potentially be due to other factors such as maturation and environment.
Further investigation into this period is of extreme interest to the , and researchers have been urged to dig up all they can on the creatures.
The use of XX121 as a weapon, its method of increasing population, incredibly violent behavior, and reaction to the presence of has lead many researchers to speculate that its origin is artificial, and that it was created as a weapon to serve these Precursors. However, there is no hard evidence in favor of this.
===The Vanishing of the UEG Resolute===
===Kalantha===
===Massacre of Kamala Station===
===Operation: ACHERON===
==Biology==
==Gallery==
==Literary Appearances==
==Trivia==
*Morphpocalypse now