Bryn, a recurring character on the Disney Channel show Jessie, is the protypical Mean Girl, just just like the Tina Fey movie of the same name. And her last name is Breitbart.
Here’s how the Jessie Wikia page for her character, played by Katherine McNamara, describes her:
Bryn Breitbart is a snobby, mean girl that attends East View High School. She was thought to be thirteenth in line for the throne of Denmark, but was then discovered to be a liar. She turned all of Emma’s friends against her in the episode Kids Don’t Wanna Be Shunned. It is revealed that her family makes toilet paper.’
A quick look at the show’s IMDB.com pages shows that many of the program’s recurring characters are known just by their first names.