Sentient animals.
Familiars are less of a race, more of a strange phenomenon where groups of animals became magical and received the ability to turn human, gaining full sentience in the process.
Familiars can be animals of any species, and not all are able to shift into humanoids.
They’re the most diverse of races, coming in many combinations.
Strangely, familiars do not have bodily needs, but can perform them if so desired.
They’re born magic, and it flows so deep within their veins that no amount of use can wear their bodies down. Between humanoids and non-humanoids, they have the most powerful magic overall.
Concept of gender varies wildly from individual to individual.
They tend to live in small, closed-off communities of the same species.
Most races tend to generally like them, and enjoy their presence, as their original role was to serve wizards of all kinds.