Remus J. Lupin is the Defense Against the Dark Arts teacher in "Prisoner of Azkaban". He is usually looking somewhat ill, and his robes look very shabby compared to the rest of the Staff’s. His light brown hair is flecked with gray, though he is quite young. This is probably due to the fact that he is a werewolf. Lupin was good friends with James Potter, Sirius Black, and Peter Pettigrew at school, and he kind of led the three of them to become illegal Animagi when they found out what he was. The four of them explored the castle in their transformations so thoroughly, they wrote the Marauder's Map together, Lupin being Moony, Pettigrew being Wormtail, Sirius was Padfoot, and James was Prongs. Though he might not be the best looking man around, he makes his lessons quite enjoyable by bringing in all sorts of magical creatures to share and battle with, and Defense Against the Dark Arts quickly becomes nearly everyone’s favorite subject. He also gives Harry Anti-Dementor lessons after they cause him to fall from his broomstick at a Quidditch match. He is utterly disliked by Professor Snape, who had a schoolboy grudge against him after Sirius Black played a dangerous joke on him, which he thought Lupin was in on. After the night when Sirius Black escaped yet again, Snape blurted out to the whole school that Lupin was a werewolf, and the great Defense Against the Dark Arts teacher was forced to resign.