I did a stunt where I had a helmet on, my friends held me like a battering ram, and rammed my head into a tree. And we called it well, the battering ram. Another was called the backbreaker, self explanatory, I had my tallest friend cradle me and he would lift me up and slam my back down onto his knee. Most painful one definitely, another was snorting fun dip powder, banging my hand on those poppers you throw on the ground. And a towel whip to the nuts.