Cartman's Sister is a deleted character who appears in the unreleased pilot episode, "The Unaired Pilot". She was seen in the scene where the Cartman family is having dinner in the dining room but does not move or speak during the scene.
She has light brown hair with a ponytail and bangs. She was seen wearing a dark pink coat, light blue pants, and black shoes. In the family portrait, she was wearing a pale green sweater, a black shirt, and dark blue pants.
According to Trey Parker and Matt Stone, the creators of South Park, Cartman's family was originally going to be larger consisting of four members (Cartman, Liane, Cartman's Father, and Cartman's Sister). However, shortly after Comedy Central adopted the series in 1997, they decided to downgrade Cartman's family to consist of only Eric and Liane because Cartman did not need a large family and thus Cartman's Sister (along with their father) were cut from the series.