NFL fans are a curious lot. They will often be loyal even when their teams are in the midst of a massive collapse (for the Cleveland Browns, that would be roughly the past 20 years).

But they can also be fickle, with the boos beginning to echo through the stadiums at the first sign of poor play.

This slideshow, however, isn't going to be dedicated to the iterations of fandom, which can be filled with the ecstasy of victory or with the absolute dejection of defeat.

Instead, it will focus on the meanies of the NFL world. These fans will yell expletives at the first sight of a rival's jersey. They'll flash the bird at referees before they even see a replay. And yes, they'll even pelt old Saint Nick with snowballs when he dares to try to bring some Christmas cheer to the stadium.