(S21E10) Touted as the 450th episode of the series, this episode was a Krusty-centric episode. Billed as part of The Simpsons 20th anniversary celebration, "Once Upon a Time in Springfield" was followed by Morgan Spurlock's hour-long Simpsons special, meaning that 75% of FOX's prime-time Sunday night lineup this week Matt Groening, instead of Seth MacFarlane; only The Cleveland Show made the cut.

This week also featured the return of Anne Hathaway, playing the character of Princess Penelope, a sudden co-host to Krusty's television show in an attempt to appeal to a wider demographic. As you can imagine, a character inspired by the Disney Princesses line can't sit well with Krusty's core (Bart and Milhouse) type of audience.