What is your favorite school tradition that isn't something you started?

I inherited a tradition from a prior teacher where there is a giant stuffed hippo that lives in the room. Once a month the kids have to guess the weight of the hippo. The kid that gets closest to the hippo's weight (which is in pounds) gets a large bag of candy. The hippo is about 2 pounds and I've been running the tradition for about 6 years now.