Noun. A fluff-bunny is somebody who claims to be of a religion they think is maligned (such as Wicca, Satanism, or Paganism) simply so that they have a reason to bitch and moan, partictularly about Christianity.
Person 1: You can't talk to me like that! You're being mean just because I'm Wiccan!
Person 2: ...No, I'm being mean because you're a weepy fluff-bunny!