A Fountain Pop
You take a big poop, freeze it in a fountain pop, then shove it back up your ass and poop it out again. You do this over and over until your guts are empty and you're just a walking poop machine.
My friend did this during a math test and got kicked out of class.
I did it in my mom's freezer and she still hasn't forgiven me.
My uncle did it on a plane and the whole row got kicked off.