Have you ever tried not naming it?
Let the players/characters be the first to ever encounter the beast. No one has ever seen it before (and lived to tell about it.) So let them be the explorers that get to name it. Maybe even have an NPC ask them, "What in the name of all that's sane do you call that?" If they kill one or more of them, let the scholarly type character bring back a few samples, the barbaric character might take a trophy, that sort of thing. Back in the city they can even be approached about it for information by a sage or a bard or such. We're talking great plot hook potential here.