There might be a creature unlocker for the wolf (I don't remember, lol) and there're a number of programs that'll change your creature's species without the official unlockers. I use the second when I want to change their species, but I've heard they can mess up the creatures...
Bare in mind that if you try to get the wolf using quest that you better be all patched up, otherwise a glitch in the game will always stop you from winning the challenge even if you get the Sister to the village.