Board Thread:Warhammer 40k General Discussion/@comment-8881468-20131229020408/@comment-18016240-20140104032425

Neithan, if it looks like a wolf, acts like a wolf, and is called a wolf, then guess what? It's a wolf. It doesn't matter if it's on Fenris, since it could easily have just been taken there as part of some bizzare zoo or studies program and mutated, the idea that it's a tyranid is just (to put it bluntly) stupid.

The humans 'turning into wolves' that you mentioned were probably just beastmen with canine features.