"Captain Underpants and the Invasion of the Incredibly Naughty Cafeteria Ladies" is a children's book by Dav Pilkey. It follows the adventures of two fourth graders, George Beard and Harold Hutchins, who accidentally turn their principal, Mr. Krupp, into the superhero Captain Underpants. In this story, the boys face a new challenge when their cafeteria ladies become evil and start causing chaos in the school. The plot thickens as Captain Underpants must confront the naughty cafeteria ladies, who have a plan to take over the school. With humor and action, the book emphasizes themes of friendship, creativity, and the importance of standing up against authority.