An Animagus (an-i-MAYJ-us), plural Animagi (an-i-MAYJ-i) is a witch or wizard who can transform at will into an animal. Third-year students of Transfiguration class at Hogwarts School of Witchcraft and Wizardry are given a demonstration of the Animagus ability by Professor McGonagall. Animagi are required by law to register with the Ministry of Magic, giving their name, the animal they become and any distinctive markings.
- Harry Potter and the Prisoner of Azkaban
- Harry Potter and the Goblet of Fire
- Harry Potter and the Order of the Phoenix
- Harry Potter and the Half-Blood Prince
- Harry Potter and the Deathly Hallows