"Mean Girls" writer

FEY

This comedian and actress also created "30 Rock" and famously played Sarah Palin on SNL.

The clue refers to Tina Fey, the comedian and screenwriter who co-wrote the 2004 hit movie Mean Girls. Her last name, "Fey," is the short answer here—crosswords often use just the surname for well-known figures. If you’re familiar with the film or Fey’s work on SNL or 30 Rock, this one’s straightforward. The clue relies on recognizing her as the creative force behind the movie’s sharp, quotable script.