In the second movie the Chamber of Secrets, Harry Potter turns into Goyle with the help of Polyjuice Potion to find out whether his arch-rival is the heir of Slytherin. However, the protagonist forgets to take off his own signature glasses, and when Draco asks him about it, he says they are for reading. Felton responds to that, saying, “I didn’t know you could read.” The Surrey-born actor later revealed he improvised that because he couldn’t remember his actual line.