This wasn't Halloween, but we have a tradition where I go to school: You dress up in costume and go out to the bars in the morning before home football games. It's called Breakfast Club and it's always hilarious.
This one time in particular, a man dressed up as Samuel Adams ran into the bar yelling "The British are coming! The British are coming!" Seconds later, 10 British soldiers entered the bar and I spit my drink all over some random person.