He's seen somebody who's actually a large, talking, bipedal deer. Tree-kid with wings is not going to throw him that much.

The squirrel is more of a problem. He fluffs up his little squirrel tail and arches his back, not sure if he's aiming for threatening or just alarmed. He has no idea how to actually interact with real squirrels, and doesn't in fact realize this is not quite a real squirrel. Yet, anyway.