I’ve had two more guesses, one non-serious (but it made me think I should write a Medusa story someday); the other was “werewolves” — which is amply suggested by “Bad Moon Rising,” but alas, is not correct.
So: last shot! This is about as obvious as it’s possible for me to get — which means still not that obvious, but enough that there’s a fighting chance:
Any takers? There’s a signed book in it for you, if you guess right . . . .