Lupin’s Wolfsbane Potion
Once a month, at the full moon, Professor Lupin transforms into a scary Werewolf and runs around trying to bite people. It’s very unseemly.
Luckily this doesn’t really happen any more, because he has a very special potion, that, provided he remembers to take it at the prescribed time, simply renders him a sleepy old wolf in need of a good lie down.
