I don't usually hold superlative contests for historical figures, so I've never considered (unlike Cracked Magazine) which historical villain was the biggest badass, but one of my former students, Jennifer Roman, tried the following, which I thought my readers would find pretty amusing (as I did):
"I tried this experiment with a fish tank once. I went out and bought five aggressive fish and named them: Adolf Hitler, Andrew Jackson, Dick Cheney, Aaron Burr (for killing Alexander Hamilton), and Osama Bin Laden. Dick Cheney ate them all. Not only that, a friend of mine forgot to give him water while I was away one summer and he still survived in like an inch of dirty water with no food. There's a lesson there but I'm still not sure what it is...other than don't mess with Cheney."