Purple Dragon Sing-A-Long Friends

The Purple Dragon Sing-A-Long Friends (formerly known as The Knuckleheads) is Jerome Horwitz Elementary School's football team.

They first appear in The Adventures of Captain Underpants, where they prance around hand in hand. They reappear in Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy - Part 2: The Revenge of the Ridiculous Robo-Boogers when Captain Kruppy the Underpants Kid ruins their biggest game of the year.