Conker's Bad Fur Day
Cute and cuddly mascots, that's where it's at, right? Conker is the one exception to this rule, and you don't want to test him. An obnoxious pottymouth with a bladder control problem, he's not exactly Teddy Ruxpin.
Given that most mothers absolutely loathe bathroom humor, this one's best avoided. There's one level where you face off against a giant monster literally made out of shit. He's called The Great Mighty Poo, and he has a song to sing for you.