What is what kind of dog is sirius black?

Sirius Black is a fictional character from the Harry Potter series by J.K. Rowling, and he is not a real dog. In the books and films, Sirius Black is an animagus, which means he has the ability to transform into a large black dog. In his animal form, Sirius Black resembles a large, shaggy dog with a sleek black coat and bright eyes. He is strong, loyal, and fiercely protective of his friends, particularly Harry Potter. Sirius Black is a central character in the Harry Potter series and plays a critical role in the story.