Companions are the scientifically created chimeras of humanoid and animal/plant DNA, first created in the town of Silverbrook by a man named Dr. M. They come in all sorts of shapes, sizes, and colors, but are generally categorized as follows.
Normals and Demis
Normals are Companions with a predominantly humanoid head/face structure - think cat girls or people with wings.
Demis are Companions with a predominantly inhuman face/head structure - think anthros or furries.
*Normal and Demi are the only two mutually exclusive categories. For instance, a centaur Companion with a horse face would be a Demi Meta, while a more traditional centaur Companion with a human head would be a Normal Meta.
Viridi
Viridi are Companions with a significant amount of plant DNA, usually enough to effect their blood, sclera, and/or skin color, though not always. Viridi do not have to be exclusively plant-based chimeras - for example, Miles has both Carnation and Vulture DNA, but still classifies as a Viridi.
Metas
Metas are Companions with a centaur/naga/mermaid-like lower half.
*Satyrs are NOT classified as Metas
Primos
Primos are a rare 'type' of Companion that had some sort of major health issue or deformity upon creation (typically a Companion-specific issue or major birth defect). Their lives are generally much harder than regular Companions, often involving a number of surgeries and major physical/mental therapy early in life. At the time of writing this, very few Primos have been created and played, and as such do not currently have their own character folder.
Pseudos
Pseudos are another rare, special type of Companion - a Pseudo is created when an adult non-Companion character (NCC) undergoes the very painful, difficult, dangerous process of gene therapy to effectively become a Companion. The Pseudoing process is heavily monitored by the Academy. Most participants are heavily encouraged to move into the medical wing on campus (or at least into one of the apartments on campus) for the duration of their treatment. Most Pseudo treatments take a year (at least) in order to complete the stabilization of the DNA splicing, as well as grow whatever new body parts are created in the process.
Severe side effects and health problems including death and cancer have been known to occur, and Pseudos also run a higher risk of genetic destabilization (also known as Crisis moments) than regular Companions. However, becoming a Pseudo has been shown to sometimes help cure those with chronic or otherwise untreatable conditions, and this is a very common reason for characters to choose to undergo the Pseudo-ing process.
Pseudos can be created from humanoids OR animals. Humanoid-based pseudos can only become Normal Companions, and animal-based pseudos can only become Demi Companions. Animal-based Pseudos never reach full human intelligence despite the additional human DNA, and will typically be ruled more heavily by their animal instincts than regular Companions might.