A World of Comics

Buddy's locker was so full of shit, it was pressurized so opening it was like firing a cannon. He was trying to blast the other kid all the way to the art room.

He misjudged the power and it blasted the kid past the art room, and all the way to the nurses office.

So the joke here is how full his locker was, or how he thought it was a good idea to use it like a cannon