"We all have arrows in our knees."
It's a fair question, really. It's a fantasy world. There could be intelligent talking skunks even without post-apocalyptic mutation.
Granted, most post-apocalyptic mutations of non-sentient beings I've seen in games haven't been chatty, but some in cartoons have been! I think. Probably. I'm failing at recalling actual post-apocalyptic examples, but there have been ninja turtle examples.