Set a school assignment about JD Salinger's Catcher In The Rye, the boys write a spoof book The Tale Of Scrotie McBoogerballs which insults Sarah Jessica Parker 465 times and causes readers to vomit.
Worried they will get in trouble the classmates claim Butters Scorch wrote the book and are furious when he is hailed as a genius.
Butters is shown obsessing over Kim, saying: "Kim Kardashian is so sexy her b**t is like a big mountain of pudding!".
Cartman suggests that as Catcher In The Rye inspired John Lennon's killer they should try and get Sarah Jessica killed, so the book will be banned.
They persuade her to dress up as a moose and to wander around a forest riddled with hunters.
Meanwhile, Sarah Jessica's husband, Matthew Broderick, 48, is seen defending his wife from Cartman's insults on a red carpet.
He says: "Obviously, I just think it's wrong to make fun of anybody's physical appearance. My wife is a beautiful woman and I know most people agree with me."
The interviewer then asks: "And Matthew, why is a transvestite donkey witch standing next to you and why is it wearing a dress?"
:: Brand-new South Park, Season 14, The Tale Of Scrotie McBoogerballs premieres on Friday, March 26 at 10.30pm on Comedy Central UK.