For a lot of the 'Harry Potter' actors, 'Harry Potter' was their first time acting in a movie, AKA they practically won the lottery. In the case of Draco Malfoy, the wizard everyone loves to hate, he had an earlier role in another popular kids movie based off of a book.
You can see Tom Felton in the fantasy movie 'The Borrowers' playing the character of Peagreen Clock, which sounds more like a character in Beauty and the Beast. "I've been turned into a Peagreen Clock!" This is a great movie to revisit since we're so used to seeing Tom Felton play the bad guy, it's not so crazy seeing him look young. It's more crazy seeing him not be so evil, but I still don't forgive him for joining Lord Voldemort.