My girlfriend would freak out if she had to walk in a mud pit, let alone if somebody used that pit to scare the crap out of her.  Check out what happens when pranks get muddy.

I imagine there was a lot of drinking before this video was shot.  I really didn't see the dude coming either.  I guess it's not very hard to hide in mud and if you've seen Predator, you know it can save your life.