Vilkacis

The vilkacis is a werewolf in Latvian and Lithuanian mythology.

It is not clear whether there is a physical transformation. As in the Twilight series.

Or if the soul actually enters the body of a wolf.  As in the Game of Thrones - A skinchanger or warg is a person with the ability to enter the mind of an animal and control it.

 

Eh--the pickings are pretty slim and I didn't want to do Vampire. 
But hey--Team Jacob, baby.