It can get pretty gloomy in an office that doesn't entertain entertainment, so to speak, where the rules aren't flexible and the work is tiresome. Nothing like a good prank to stir things up, right? Just don't get caught, or it'll cost you. Once the coast is clear, you can set up your prank and leave unnoticed. For those of you who work in not-so-stuffy offices, these pranks are great to play on someone, especially on a gloomy Monday morning.