The Simpsons/Sherrie and Terrie

Two rather sickly looking twins with purple hair. They are in the same class with Bart. In one episode it is revealed that their father is Homer's supervisor at the power plant. He fires Homer for causing an accident while waving to Bart from a cart during a school tour of the plant.

The girls themselves dress alike, reinforcing their "twin-ness". They are quite stuck up, and never miss an opportunity to berate Bart. However, early on in the series, they had different personalities entirely, and at one point they both kissed Bart (trying to remember what the circumstances were, at a birthday party?).

They are some of the few original characters at this point that have not had an episode exploring their personalities and lives in detail.