Professor Lupin is Harry's new Defense Against the Dark Arts class. Every kid in Hogwarts likes Lupin, except Malfoy and his friends. He is one of the Mauderers. Yes, he can change into an animal. It's called Animagus. But he didn't just choose. When he was younger, he got bit by a werewolf. Now every full moon, he changes into a werewolf. That's where the screams come from in the Shrieking Shack (some people think it's haunted).