Professor Filius Flitwick was the Charms master and head of Ravenclaw house during Harry's first year at Hogwarts. He is described as "the best and most knowledgable Charms master alive in the world today." He has a remarkably short stature - Rowling has stated that he has "a dash of goblin blood."
Professor Flitwick enters the Three Broomsticks with Professor McGonagall, Hagrid and Cornelius Fudge. Like McGonagall and Madam Rosmerta, Flitwick remembers James Potter and Sirius Black when they were at Hogwarts. He tells the table that the boys were inseparable, like brothers. Flitwick explains the spell Lily and James Potter used to protect themselves from Voldemort, the Fidelius Charm.
Professor Flitwick is seated at the staff table for the Sorting Ceremony, next to Professor Sprout. Due to his short height, Flitwick has to have a large pile of cushions on his chair so that he can reach the table.
During his Charms lesson, Professor Flitwick teaches the students how to practise the Banishing Charm. Due to Neville's poor aim, Flitwick finds himself on the end of the Charm, flying across the classroom instead of Neville's cushion.
Professor Flitwick assists Professors McGonagall and Sprout in helping Professor Trelawney back to her lodgings. Using a Locomotion Charm he carries her trunks up the Entrance Hall stairs.
Professor Flitwick attends the Apparition lesson in the Great Hall in his capacity as Head of House along with Professors Snape, McGonagall and Sprout. When Susan Bones splinches herself, the teachers converge around her, reattaching her left leg in a puff of purple smoke.