The actor played two distinct versions of Professor Flitwick in the first two movies — in “Harry Potter and the Philosopher’s Stone,” and “Harry Potter and the Chamber of Secrets,” he portrayed an old, grey-bearded wizard. In “Harry Potter and the Prisoner of Azkaban,” we see a much younger Fillius Flitwick who sports a snazzy mustache and conducts the Hogwarts choir. The changes in the character aren’t addressed in the films, and Davis isn’t referred to as the Professor in the third, but it is presumed the transformation had to do with the director’s vision at the time. Christopher Columbus directed the first two and wanted to stay faithful to the source material, which describes Flitwick as a small, old wizard with a white beard who would stand on a pile of books to teach.
In a 2009 interview with ET Canada, the actor looked back at his “Harry Potter” days and detailed how he was always meant to play Professor Flitwick.
“I’m very fond of Professor Flitwick, he was a teacher of Charms. It was my first day on the ‘Harry Potter’ movies, that sequence where I taught Hermione to levitate the feather … I was just so fond of that character.”