Harry Potter and the Prisoner of Azkaban attacked by a big black dog, which Harry has seen several times before. The dog drags Ron through a tunnel under the Whomping Willow into the Shrieking Shack. Harry and Hermione follow, and there is a brief standoff when they find Ron with Sirius Black, who has transformed from the dog. Lupin enters, and they explain the situation to Harry and his friends: Lupin is a werewolf, which led to his friends James Potter, Sirius Black, and Peter Pettigrew becoming animagi. Lupin explains that Scabbers is Pettigrew in his animal form; he has been hiding from Black, whom he had
Harry Potter and the Prisoner of Azkaban games loosely based on "Harry Potter and the Prisoner of Azkaban" were also released for several platforms, and most obtained favourable reviews. Harry is back at the Dursleys for the summer holidays, where he sees on Muggle television that a convict named Sirius Black has escaped, though with no mention of what facility he has broken out of. Harry involuntarily inflates Aunt Marge when she comes to visit after she insults Harry and his parents. This leads to his running away and being picked up by the Knight Bus. He travels to the Leaky Cauldron where he meets Cornelius Fudge,