When playing The Sims 3, using official community content, the game can malfunction, turning your characters into centaurs. The glitch seems to strike the most when Sims have sex, or maybe it's a secret STD the devs don't tell you about to protect sales, who knows.
The characters not only become centaurs but also gain breasts that may not get censored, unlike any other instance of nudity in the game. While adjusting to life as a beast of myth might be tough ("I just bought all these jeans ..."), you'll be happy to learn that they can still ride a bike despite all.
And it's not always sex-related. The glitch can somehow also affect kids, and oh boy, they sure are the ones poised to suffer the most. Symptoms include head and chest switching places, and ultra-long fingers. Please, think of the Lovecraftian children.