What happens to fur/feathers/etc that a wizard's Animagus form might shed? Do the bits stay as they are (Padfoot sheds, I assume)? Do they revert to, er, people hair?
What would happen if you picked up a bit that was (unknowingly) from someone in their Animagi form and used it in Polyjuice potion? Would you turn into the person? Or into their Animagi form?