Lupin Reveals that There Were Three Unregistered Animagi at Hogwarts

PAGES: 351-352

Hermione Granger questions how Peter Pettigrew could be an Animagus without being on the Ministry's official register. Remus Lupin explains that he, Sirius Black, and James Potter had become unregistered Animagi during their time at Hogwarts in order to accompany Lupin during his werewolf transformations. Lupin reveals that Scabbers is, in fact, Peter Pettigrew in his Animagus form.