If there are bunnies, they'll be Bunny-Wights, raised by the Others after being frightened to death...
Well, ok, they might also be Vorpal Rabbits, but the Holy Hand Grenade is woefully unpresent, so such an encounter could be very dire for those involved...hmmm...
You know what? I think I've just come up with the next challenge for my players; vorpal bunny-wights.