Rita Skeeter was able to turn into a blue beetle. He first learned how to do it in order to help control Remus Lupin when he became a werewolf. He used his unregistered form to hide as ‘Scabbers’, which is the pet rat of the Weasley Family.
Peter Pettigrew was able to turn into a grey rat. Since McGonagall taught Transfiguration, she was able to teach her students about Animagi both theoretically and practically. McGonagall was one of the few people who has their form registered with the Ministry of Magic. A cat is also what her Patronus takes the form of. Professor McGonagall was able to turn into a silver tabby cat. Like Sirius, he used his unregistered form to help control Remus Lupin when he turned into a werewolf. James Potter was able to turn into a stag, which is also the same form that his Patronus Charm takes the form of. As a large black dog, he was able to safely accompany Remus, along with James Potter and Peter Pettigrew.
Before that, he used his form to help control Remus Lupin when he turned into a werewolf. He used his unregistered form to escape from Azkaban prison. Sirius Black was able to turn into a black dog. Here are some of the forms that are known and also some more details about each of them.
