"Pulling a Charlie Sheen" has basically become slang for doing lines of coke off a call girl in a hotel room, so it's surprising that Sheen isn't the craziest person in this scene. Oliver Stone's vintage Vietnam War movie Platoon featured a number of brutal characters, but none were worse than the inaptly named Bunny â€” basically a high school bully with a shotgun and a sociopathic attitude that would make the door gunner from Full Metal Jacketcringe.
In this less famous coda to the infamous "dance motherfucker!" scene, the psycho beats a disabled man to death in front of his squad mates and is disturbingly pleased by the result. It's not surprising that The Simpsons never did a parody of this one... Check out the scene here.