Hiya!

If you're talking about Bigfoot, the Ogopogo, and Jackalopes, then I don't see why they wouldn't be a (quiet) part of this world. If you're talking bout were-creatures, then that's fine too. I'm surprised nobody's written a werewolf character, not that I'm necessarily complaining. :3

And if you show me that your mute character works really well with the world and the other characters and in general is a character I would let into the game, I'll let them into the game. That's rather a tautology, but it's the best I can do right now. In general, I have few limits on characters - they just have to be interesting, complex, work well with the story, and all the other nonsense I put in the first post.