Well, you've got steel types like Aggron that have some pretty nasty fangs. Mawile's hair looks like a big, metallic mouth, too.

[And then there's Steelix, but its teeth are flatter. Probably designed for grinding up metal.

At any rate, Riku watches Rin try to pry off his dog for a few seconds before adding--]

Just take it slow. It might hurt a little, but I think you'll be okay.