"Becoming an Animagus - meaning a wizard who can turn into an animal - isn't so much illegal as...well, it's supposed to be regulated by the government, and it's a long training process and all that rot, because yeah, you can get stuck halfway between human and animal, or trapped entirely in the animal's body....or have the animal's mind in your body....it's not cool. But, uh, I'm self-taught and the government hasn't got the least notion I've done it, so. Very illegal."