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
Magical creatures in Harry Potter Magical creatures in Harry Potter Magical creatures are an aspect of the fictional wizarding world contained in the "Harry Potter" series by J. K. Rowling. Throughout the seven books of the series, Harry and his friends come across many of these creatures on their adventures, as well as in the Care of Magical Creatures class at Hogwarts. Rowling has also written "Fantastic Beasts and Where to Find Them", a guide to the magical beasts found in the series. Many of these are derived from folklore, primarily Greek mythology, but also British and Scandinavian folklore. Many of the legends surrounding mythical