In the Bloody Roar series, the majority of Zoanthropes are primarily mammals and feline. Whether or not a feline alter-ego is the dominant type is uncertain; the games do not go farther into the background of Zoanthropes outside of the main characters in-game. Zoanthropes seem to be a natural occurrence however as many of the characters seem to be born with the ability. It also appears the ability can be passed on through a family bloodline as evident by Yugo gaining his abilities from his father who was a natural Zoanthrope.
However, it is a common theme in the games that a Zoanthrope transformation can be forced by experimentation. Alice is an example of a Zoanthrope experiment that resulted in success. Experiments conducted on Stun made him a Zoanthrope, but the result was an unstable and deformed body. Uriko was a victim of too many experiments, and therefore has an altered, lesser beast form instead of her original Chimera form.
It is also suggested in Bloody Roar 4 that Zoanthrope abilities can be passed from a Zoanthrope to a human, though this has only been proven in regards to the Unborn. Xion stabbed Nagi and she became the Spurious. The games never expand upon the idea of a bite or a scratch from a Zoanthrope mutating humans into beasts.
Zoanthrope could comes from the term "Zoanthropy", a mental disorder in which one believes oneself to be an animal.
"zoo" comes from the greek word "zỗ̩on" which means "animal" and "-anthrope" come from the greek word "ánthrôpos" which means "be human"
We can establish the link with the word "lycanthrope" (lukanthrōpos - lúkos (loup) / ánthrôpos) which means werewolf.