Nope, you can't transfer yourself into an animal, at least not on the physical plane. It is possible while on the astral plane to take the shape of an animal if you like, but it isn't tranferable to the physical plane.
And if you mean a curse to turn someone into a werewolf, well that won't work either. That's why we keep putting the werewolf spells into the fantasy section. Werewolves do not exist. They are the result of Medieval misunderstanding of medical issues that frightened them.