|Voiced by||April Stewart|
|First Appearance||Free Willzyx|
The girls' official "List Keeper" in difficult times, Nelly is a member of the extended fourth grade class at South Park Elementary.
She was first seen in Denver the day the boys met Willzyx by the stingray touch tank. Later, when Butters tried to kick her in the 'balls' to obtain the Cutest Boys list, she beat him up and broke his arm in return. She was also a viewer of his 'What, What in the Butt' video. She also keeps the girls' hideout clean when the New Kid forges an alliance with them.