Lycanthropy, like vampirism, also comes in the form of a virus. It's characterised by the infected changing into an anthro-like beast form during times of extreme emotion or during certain days(typically during a full moon, however it seems this may be a coincidence). There's no known number of strains, though they seem limited to earth animals and cycles of 16, 24, or 32 days. A select few learn to take on a feral form, which is slightly larger than the animal of their strain.
The virus is transmitted via bites. There's a 50% chance that the individual simply is immune to the effects, and thus does not take on the shapeshifting abilities.
Lycanthropy can be caught in the ARPG via battling and cured via a quest.
In the future, we will detail yena-specific strains.