I've never heard of anyone speaking to frogs, but it's an interesting idea.

[ so he must have some magic. you don't just start yapping to rats without some inherent magic. ]

I've heard tall tales of Chasind hedge witches who can transform into animals. I used to always dream about that as an apprentice - turning into a cat and slipping out the door. Or a tiger, and mauling the Knight-Commander.