Jo Frost is a professional nanny and host of the program Supernanny.
In "Tsst", Liane Cartman hired Nanny Frost to help her control her son Eric's behavior. She was initially confident, declaring, "There's no trial too tough for Super Nanny! In just three days' time, you're going to see a new Eric Cartman!"
Three days hence, Frost was institutionalized at Slater-Carey Mental Hospital, where she now spends most of her time sobbing and eating her own excrement. Between mouthfuls of defecate, she screams that Cartman comes "From hell!"
She appears in a purple cardigan and dress and wears rectangular glasses. She appears slightly overweight and has a mole on her left cheek. She is also at one point seen with a parasol patterned with the colors of the Union Jack. Like many British characters, she is shown to have bad teeth.
After being institutionalized, she is seen in a white mental patient's uniform, with messed up hair and covered in her own feces.
- In the opening title sequence to Supernanny, Frost is seen with numerous South Park children, including Heidi Turner, Milly, Pete Thelman, and Damien.