So this is just a shortlist of mean girls because they have been a part of cinema since the silent era of cinema. Some things about mean girls:
1. they are usually skinny, white, and blond (or brunette), there are exceptions to the rules
2. they are usually popular, but sometimes the mean girl is a misfit (ex. Janis Ian from Mean Girls)
3. some of these characters are depicted as borderline sociopathic.
4. they sometimes are also phobic or racist in some way, but it is usually just expressed as a part of their "meanness".
5. these characters range from iconic to not so iconic.
Note: Courtney and Whitney are from Bring it on not Mean Girls (typo)
Enjoy.
