Hogwarts' resident paranoid and eccentric old man. His character (especially in the fourth book) was an asset to Rowling and made the story flow well (even though it was an imposter) :P

hes serious but loony

Mad-Eye Moody is one of my many favorites. I love the way his mind works and I think JKR brought him in in a great time. He had been locked in a trunck for a year and now he is even more suspictious of everything. Like cheaking his drink for poisons. And how his eye is now everywhere. His character is so funny. Just the way he does stuff and knows everyting going on becuz of his magical eye. I just hope he shows up more in the books and makes a good apearence in the movies.