Background gags

Touching up background details of a minute long animation of Dave bullying his teacher that takes place in a classroom / school hallway. I already have things like house of beck and lipstick academy in mind, are there any other small bags that'd fit as someone's t-shirt, on the blackboard, or a classroom poster?

I dont plan to leave a single frame without a reference to something, anything from the sleepycabin days and onwards, already working on Cory's black binder