Becoming an Animagus in the Harry Potter series is long, dangerous, and complicated - and not the sort of thing Harry would have found instructions for in his Transfiguration textbook. It takes several months to execute, especially if efforts fail (which is likely). A hopeful Animagus must be a master in Transfiguration and Potions since both facets of magic are required. This has proven unachievable for most witches and wizards, with only the especially impressive known to have been successful.

Harry first learned about Animagi in Harry Potter and the Prisoner of Azkaban. Minerva McGonagall, Sirius Black, James Potter, Peter Pettigrew, and Rita Skeeter were each revealed to have the ability to turn into an animal at will, which means they went through a grueling process (most illegally). Though the Harry Potter books or movies never went into full detail about what this process included, the Wizarding World website has...