You’re mental,” said George, trying to push it back at Harry.“No, I’m not,” said Harry. “You take it, and get inventing. It’s for the joke shop.”“He is mental,” Fred said in an almost awed voice. [Goblet of Fire]

Moony, Wormtail, Padfoot, and Prongs,” sighed George, patting the heading of the map. “We owe them so much.”“Noble men, working tirelessly to help a new generation of lawbreakers,” said Fred solemnly.“Right,” said George briskly. “Don’t forget to wipe it after you’ve used it —”“— or anyone can read it,” Fred said warningly.[Prisoner of Azkaban, Chapter 10]