I've gotten hooked on this show in Cartoon Network. In the episode "Donny", the heroes run up against Why-Wolves, "Creatures possessed by the spirit of inquiry . . . and bloodlust!".


The basic Why-Wolf (all the designs are by Phil Rynda)




Feral Why-Wolf. Grrrrrrr!




The Why-Wolf in its more civilized form (this is what they turn into, instead of humans)




A biclops Why-Wolf (they don't really explain what's going on with this sucker)




There's also a vampire character who takes on wolf form in a different episode:



Cute stuff!