Season 5 Episode 10 – Don't Look a Smith Horse in the Mouth

When Stan gets told by Francine to get rid of his gas-guzzling SUV, he and Roger hatch up a plan at the local horse track to avoid losing his car. When Stan gives manual sex to the horse (even though Roger was joking), the horse becomes traumatized so they switch minds with Stan and the horse. Meanwhile, Steve and his friends help an old friend who has become an overweight shut-in, Mr. Tuttle. Snot is volunteered to retrieve Mr. Tuttle's wallet from his back pocket, but becomes trapped under him. Steve uses Stan (whose body still has the horse's mind) to lift Mr. Tuttle and free Snot.