20 Costumes for Complete Assholes
Interestingly enough, browsing the "Humor" section of most major costume sites is quite possibly the worst way to find a funny costume. Unless of course your definition of "funny" is somebody's bearded 46-year-old father reciting a bunch of dick jokes from the unauthorized Porky's 4 script he wrote in 1987. If this is the case you will likely find most of the costumes I have selected below to be pretty awesome (as opposed to offensively unfunny and pathetic).
Most of these costumes are based solely on terrifyingly bad near-puns, but you'll even find quite a few (such as "Big Balls Scratch Off" above) in which the designer has simply taken an ill-conceived "naughty" concept (in this case, balls, tee-hee!) and combined it with some arbitrary item in order to make it into a shitty costume.
So look forward to that, I guess.
And since I stole a bunch of their images, I might as well give THE COSTUME SITE I FOUND THIS OBJECTIONABLE MATERIAL AT some credit.
Although I have never purchased anything there, I highly recommend it for all your mysogenistic costume needs!