Peter Pettigrew

As a student at Hogwarts, Peter Pettigrew had been best friends with fellow Gryffindors James Potter, Sirius Black and Remus Lupin. As young wizards, they discovered how to transform into Animagi, and Peter made use of his rat-form when he disappeared from the wizarding world after the murder of James and his wife, Lily Potter. Pettigrew (or Wormtail) became one of Lord Voldemort's most loyal servants - a far cry from the company he kept in his Hogwarts days.