Peter Pettigrew
Peter Pettigrew is the wizard whose betrayal of his closest friends set the entire plot of Harry Potter and the Prisoner of Azkaban in motion. For twelve years, the wizarding world believed him to be a hero murdered by Sirius Black, when in truth he was the traitor who had sold out James and Lily Potter to Lord Voldemort, then faked his own death and lived in hiding as a rat. His exposure in the Shrieking Shack forces Harry to confront the deepest questions of justice, mercy, and the nature of evil.
Identity and Background
Peter Pettigrew was a student at Hogwarts School of Witchcraft and Wizardry in the same year as James Potter, Sirius Black, and Remus Lupin. He was a short, plump boy with a talent for attaching himself to stronger, more charismatic friends. As Lupin later described him, Pettigrew "always liked big friends who'd look after him." He was never in the same league as James and Sirius in terms of talent, but he was clever enough to become an unregistered Animagus, transforming into a rat — a form that suited his nature. Along with James (Prongs the stag), Sirius (Padfoot the dog), and Lupin (Moony the werewolf), Pettigrew (Wormtail the rat) was one of the four Marauders who created the Marauder's Map and roamed the Hogwarts grounds at night. When the Potters went into hiding from Voldemort, Sirius persuaded them to switch their Secret-Keeper from himself to Pettigrew at the last moment, believing that Voldemort would never suspect such a "weak, talentless thing." Pettigrew promptly betrayed them, passing information to Voldemort for a year before leading him to the Potters' home.
The Betrayal and Faked Death
On the night James and Lily were murdered, Sirius Black cornered Pettigrew in a street full of Muggles. Before Sirius could curse him, Pettigrew yelled for the whole street to hear that Sirius had betrayed the Potters. Then, with his wand hidden behind his back, he blasted the street apart, killing twelve Muggles and the wizard Peter Pettigrew — or so it appeared. In reality, Pettigrew had cut off his own finger, transformed into a rat, and escaped down a sewer. The Ministry of Magic found only his finger and a heap of bloodstained robes. He was awarded the Order of Merlin, First Class, posthumously. For twelve years, he lived as Scabbers, first as Percy Weasley's pet rat, then as Ron's. He grew thin and balding, his fur falling out, his body showing the strain of his long deception.
Life as Scabbers and Exposure
As Scabbers, Pettigrew slept in Harry's dormitory for three years, perfectly positioned to act if Voldemort's supporters ever regained strength. He never harmed Harry during that time because, as Sirius later explained, he was not about to commit murder under Dumbledore's nose for a "wreck of a wizard who'd lost all of his power." He was waiting, listening for news that his old master might rise again. When Sirius escaped from Azkaban and saw Pettigrew's picture in the Daily Prophet on Ron's shoulder, he knew where to find him. Crookshanks, the extraordinarily intelligent cat, recognized Pettigrew for what he was and tried repeatedly to bring him to Sirius. Pettigrew grew increasingly desperate, biting himself to leave blood on the sheets and faking his own death a second time. In the Shrieking Shack, Lupin and Sirius forced him to transform back into human form. He emerged as a short, balding man with a pointed nose and small, watery eyes, his missing finger the only remnant of his faked death.
Confession and Harry's Mercy
Confronted by his former friends, Pettigrew confessed. He had been passing information to Voldemort for a year before the Potters died. He had been scared, he whined, and Voldemort would have killed him. Sirius's response was savage: "THEN YOU SHOULD HAVE DIED! DIED RATHER THAN BETRAY YOUR FRIENDS, AS WE WOULD HAVE DONE FOR YOU!" As Black and Lupin prepared to kill him, Harry intervened. He could not let them become murderers, even for Pettigrew. "I'm not doing this for you," Harry told the groveling traitor. "I'm doing it because — I don't reckon my dad would've wanted them to become killers — just for you." Harry spared Pettigrew's life, intending to hand him over to the Dementors. But during the chaos of Lupin's werewolf transformation, Pettigrew escaped, transforming back into a rat and fleeing into the night.
Consequences and Thematic Significance
Pettigrew's escape carries profound consequences. Dumbledore later tells Harry that by sparing Pettigrew's life, Harry has created a bond of debt: "When one wizard saves another wizard's life, it creates a certain bond between them." Pettigrew owes his life to Harry, and Dumbledore predicts that the time may come when Harry will be very glad he saved Pettigrew's life. This act of mercy, against all justice and revenge, becomes one of the most morally complex moments in the series. Pettigrew is a study in cowardice and the corruption of loyalty. He is the friend who sold his friends for his own skin, the hero who was a traitor, the pet who was a spy. His transformation into a rat is not merely magical but symbolic: he is a creature that scurries, hides, and survives by any means necessary. His exposure shatters the story Harry has believed about his parents' death and forces Harry to choose between vengeance and the kind of mercy his father might have shown.
