Peter Pettigrew

Peter Pettigrew, better known as Wormtail, is a villain from the Harry Potter series who was one of James Potter's friends. Later, he joined the Dark Lord and betrayed James and Lily Potter to serve as the main human antagonist in Harry Potter and the Prisoner of Azkaban.

After being hunted down by some Muggles for some unspecified crime, he blew them up with a spell and blamed the murders on his friend and Harry Potter's godfather, Sirius Black. He then faked his own death by cutting off one of his fingers and leaving it at the crime scene, then turning in to his Animagus form, a rat. After which, he encountered Percy Weasley, who kept him as a pet and named him 'Scabbers' due to his mangy appearance. He remained this way for 12 years and was eventually passed down to Ron Weasley.

Wormtail was eventually forced to reveal himself by Sirius Black and Remus Lupin, who were angry for framing the former for the murders. Wormtail told him them that he was forced to do it out of fear, but Remus, knowing it to be a lie, then tried to attack him, but Harry defended him, which Peter replied that he owed Harry a life debt. But, before he can be charged for his crimes, Lupin begins to turn into a werewolf and, amongst the confusion, Wormtail escapes in his rat form.

After finding a dying Voldemort, Wormtail organized the events of the Triwizard Tournament disasters, murdered Cedric Diggory - on Voldemort's orders - and helped Voldemort rise again in a ritual which required Harry's blood and his own hand. As reward of this, Voldemort gave him a new Silver Hand. In the last book in the Harry Potter series, Harry Potter and the Deathly Hallows, he kidnapped Harry and Ron and held them hostage in a dungeon along with several other prisoners. After Harry mouthed off at him, he attempts to kill him but Harry reminds him of the debt he owed him and he hesitates, which makes the silver hand strangle him to death.

In film
Wormtail's role in the films is quite the same as in the books, exception being his final scene.

He was friends with James Potter, Sirius Black, and Remus Lupin at Hogwarts. The four of them wrote the Marauder's Map. Although this was never explicitly stated, all future movies referred to Peter Pettigrew as Wormtail, and Sirius was referred to as Padfoot a few times.

His cowardice and desire to be with the most powerful side caused him to betray Lily and James to Voldemort, resulting in their deaths. When Sirius confronted him, Wormtail cut off his finger and used a Blasting Curse to blow up twelve Muggles, transforming into a rat so that everyone would think he was dead, framing Sirius, who was believed to be Voldemort's second in command and locked in Azkaban.

From here, he stayed a rat, and became Ron's brother Percy's rat, Scabbers. His first appearance was in the Philosopher's Stone movie. The only major difference from his role as Scabbers is in Chamber of Secrets; In Professor McGonagall's Transfiguration class, they were supposed to transform animals into water goblets. Ron was transforming Scabbers, but his wand was broken, incompletely turning him into a goblet with fur and a tail.

In Prisoner of Azkaban, Crookshanks was chasing after him. He faked his death to avoid being killed by Sirius, who was hunting him again. It is unclear if Crookshanks was working with Sirius (as he was in the book), or if he was trying to eat him. Eventually Sirius and Lupin revealed Scabbers's true identity. They intended to kill him for his betrayal, but Harry asked them to spare him. As they were about to turn him over to the Dementors, Lupin transformed into a werewolf, as it was a full moon, allowing Wormtail to turn into a rat and escape.

He went back to Voldemort, restoring him to a rudimentary body with Barty Crouch, Jr., who eventually got Harry to the graveyard by turning the Triwizard Cup into a Portkey, as Voldemort wanted Harry's blood. Wormtail put Voldemort's father's bone into a cauldron, cut off his own hand (for flesh of the servant), and cut Harry's arm for his blood, returning Voldemort to his original form. As a reward, Voldemort gave him a silver hand.

He had a brief cameo in Half-Blood Prince, answering the door when Bellatrix Lestrange and Narcissa Malfoy came to the house where he and Snape were at. After Bellatrix and Narcissa were inside, Snape shut Wormtail outside the door.

In Harry Potter and the Deathly Hallows: Part 1, he was assigned to keep Ollivander quiet. He also locked Harry and Ron in the cellar of Malfoy Manor when Bellatrix was torturing Hermione for information. She later sent Wormtail to get Griphook to confirm whether the Sword of Gryffindor had been stolen from her vault at Gringotts. After Dobby left with Ollivander and Luna, Wormtail came down to check on the prisoners, but was hit in the back by Dobby with a magic energy ball, and, after saying "Ow!", collapsed to the ground. Dobby took his wand and gave it to Ron. This is the only departure from the book; the filmmakers thought it would be deemed too graphic for a man to kill himself even if it wasn't his choice (despite being able to show Cadmus Peverell hanging himself, as well as giving Snape a graphic and gory death scene in Part 2).

It is unclear whether he killed or stunned him; the filmmakers said he was stunned back when they were intending him to reappear in Part 2; however, David Yates has announced that he will not appear in Part 2. It should also be noted that when Harry stuns Umbridge and Mafalda Hopkirk they are both knocked out instantaneously, while Wormtail stayed alive/awake for a few seconds, and apparently suffered a great deal of pain. It is presumed that either Wormtail was killed from Dobby's attack, that Voldemort killed him when he arrived at Malfoy Manor, or that he was one of the 17 Death Eaters disintegrated trying to get through the Hogwarts barrier.