Filius Flitwick is the Charms Master at Hogwarts and the head of Ravenclaw house. He is a very short, dwarf-like man. In "Harry Potter and the Philosopher's Stone" he uses his magical skills to help decorate the Great Hall for Christmas. He is also one of the teachers who cast spells to guard the Philosopher's Stone by putting charms on a hundred keys so they can fly, making it difficult to find the key to the door leading to the next chamber.