Sirius Black is a powerful wizard. He meets James Potter at Hogwarts, and the two become best friends. He comes from an old wizarding family but rejects their views that pure-blood wizards are more superior, instead fighting against Voldemort during the First Wizarding War. He is Harry’s godfather, but this is not revealed until after Sirius escapes the wizarding prison Azkaban, where he was wrongly imprisoned for a crime he did not commit. He has to live his life as a fugitive as he is considered a dark wizard by the rest of the wizarding world. Harry finds out the truth, and the two continue to communicate in secret. Sirius Black is an Animagus, he can transform himself into a dog, at will.