Sia is a student at South Park Elementary who first appears in the Season Eighteen episode, "The Cissy". Although no other character refers to her by name in the episode, her voice credit is listed as "Sia".
She has very pale short blonde hair with bangs. She wears a short black jacket over a black-and-white striped shirt, with a red skirt.
Sia exhibits frustration and anger at Cartman's refusal to leave the girls' bathroom.
- ""South Park" The Cissy (TV episode 2014)". IMDb.com.