Harry showing Fred and George old muggle movies. Fred and George jumping onto the table in the great hall and yelling for a food fight. Good platters magically refill so that there's no end in sight. Ravenclaws getting way too into it and building a shelter. Hufflepuffs being surprisingly good at finding just who to hit to antagonize any house in order to keep things going. Gryffindors immediately getting into an all out war with Slytherins. Magic being used at first but then it's just the satisfaction of throwing with your hands and dumping food on your friends. The entire room freezing and not saying a word when McGonagall gets a pie to the face. The entire room breaking into a bigger war when they realize Dumbledore was the one who hit her.
