You can pick just about any of the Jackass films for a decent shot of damage being done to the male genitalia, but one of the opening scenes in Jackass Number Two takes the cake for pure wince factor. In the bit, Chris Pontius has placed a sock over his manhood and inserted it in a hole that leads to a small reptile aquarium - inside of which is a snake. To make things more fun, the sock is dressed to look like a mouse. Johnny Knoxville puppeteers the Pontius puppet, teasing the snake via a string tethered to the tip. What happens next is exactly what you hope (and fear) will happen. The snake clamps down on the tip and won't let go. It's hard to know whether to laugh or cry at the sight of this - most will probably do both.