Lycanthrope
There are "True" lycanthropes and "Afflicted" lycanthropes. True lycanthropes are born with the ability to convert between an animal and hybrid animal form, along with a humanoid form in many cases. They can do this at will and are not dependent on any triggering factors.
Afflicted lycanthropes are pretty much the same, except that they were not born with this ability but rather obtained it through being bitten or scratched by another lycanthrope. For them, it is a disease. These lycanthropes most often do not have full control over their form changes, and can be forced to change sometimes through triggers.
Lycanthropes known on Avlis include wererats, weretigers, and werewolves. They are governed by the demigod Xenon.