In 1993, Sirius Black escaped from Azkaban after seeing a picture of Pettigrew's rat form in a Daily Prophet article about the Weasley family's trip to Egypt.
Peter was taken in by the Weasleys and for twelve years lived with them as Scabbers. One day, while in Azkaban, Sirius asked Cornelius Fudge for his newspaper and saw a photo of Scabbers (aka Peter). Realising he was at Hogwarts, Sirius escaped to come and find him.
As this left a large amount of incriminating evidence against Sirius, who had been laughing maniacally due to believing Peter has finally died, he was arrested and, without a trial, sent to Azkaban for the next twelve years.
An exasperated Lupin gives each one of them back their wands, and explains that he was examining the Marauder's Map, watching Ron, Harry and Hermione exit Hagrid's cabin, when he saw the name Peter Pettigrew alongside Ron's. At that point, he realized that Peter must alive and disguised as Scabbers.
He Chose The Weasleys As Owners To Avoid The Death Eaters
Due to the fact that Voldemort's apparent demise happened due to Pettigrew's information, the Death Eaters believed that Pettigrew was a traitor and therefore sought to destroy him.
How Did Sirius And The Potters Get It So WRONG With WORMTAIL
Why did Fred and George never see Peter Pettigrew?
There are hundreds of students in Hogwarts, plus ghosts, teachers, House Elves, and Peeves. Unless Fred and George were watching Ron sleep on the map (which would be creepy), they wouldn't have noticed Pettigrew. It's only possible to see a human changed in his animagus form if you know the person is one.
Lupin didn't know Peter had survived. He was like everyone sure that Sirius had obliterated Peter in their duel. He only recognized Peter when Sirius insisted that Peter was the one who killed all those muggles, then he cut of his finger and ran of. “All that was left from him was one finger”.
Werewolves might be dangerous to humans, but they don't attack other animals; so Lupin's friends found a way to stay together as a kind of pack. James's Animagus form was that of a stag, which earned him his nickname, Prongs.
As James and Lily's Secret-Keeper, Pettigrew was entrusted with the information of the Potters' hiding location in Godric's Hollow. He had not even been Secret-Keeper for a week when he handed the information over to Voldemort.
Sirius Black is introduced in the third Harry Potter installment as the Prisoner of Azkaban, a dark and menacing figure feared by the Wizarding World almost as much as Voldemort himself. Everyone believes he's a mass murderer who betrayed Harry Potter's parents to the Dark Side.
Until the climax of Prisoner of Azkaban, Lupin believed Sirius Black was guilty of murdering 12 Muggles, betraying Lily and James Potter, and killing Peter Pettigrew. He eventually discovered the truth — that Sirius was innocent, and the very much alive Peter was the traitor.
Peter Pettigrew, the Secret Keeper for the Potter family who betrayed them to Voldemort. Sirius Black was originally meant to be the secret keeper for James and Lily Potter, but Sirius thought Voldemort was on to him (he thought that Remus Lupin was a spy), therefore passing on the Secret Keeper to Peter Pettigrew.
Scabbers is Ron's rat, but later in the book it is revealed that he is really the wizard Peter Pettigrew who has taken a rat form. The Weasley family adopted Scabbers (the rat) thirteen years ago; he used to belong to Percy but was passed down to Ron when Percy got an owl.
As a result, the Ministry abandons its stance that Voldemort has not returned, and Dumbledore is trusted once more. He, in turn, persuades the Minister that Sirius is innocent. By the following book, Sirius is exonerated; unfortunately, it is far too late.
Dumbledore's lack of belief that Sirius is innocent is also suspect. Sirius was a member of the Order of the Phoenix which fought against Death Eaters, but Sirius also was as close to James as a brother, the Potters even took him in when he ran away from home.
Unfortunately, Pettigrew was the actual spy among the group, and he told the secret (which was the location of Godric's Hollow) to Voldemort, leading to the deaths of Lily and James.
He was imprisoned for crimes that he didn't commit (killing Peter Pettigrew and a bunch of muggles, betraying his best friend, James Potter, and his wife Lily Evans, being the right-hand man of Dark Lord Voldemort and who knows what else?)
J. K. Rowling has stated that she would fancy an otter — her favourite animal — as her Animagus form, though if she actually transformed, she suspects she might be "a guinea pig or something, which would be quite embarrassing."
His entire demeanor throughout the series suggest that Dumbledore was asexual for the rest of his long life. He died a 115 year old virgin. Lupin- Due to him being a werewolf, it's very likely he didn't lose his virginity until he met Tonks.
Scabbers was actually, as we know, Peter Pettigrew, an unregistered animagus hiding out as the Weasley's pet rat. No matter how hard he focussed his intention on turning the rat yellow, or even if he'd said the words rattus colovaria (erm, we did our best) the spell would never have worked because the rat wasn't a rat.
Remus fought at the Battle of Hogwarts on 2 May 1998, during which his wife was murdered by Bellatrix Lestrange. Remus was also murdered by Death Eater Antonin Dolohov, during the first half of the same battle. His death was possibly avenged by Filius Flitwick.
