Principal Benjamin "Benny" Krupp is the principal of Jerome Horwitz Elementary School, a major character in the comics and the (former) secondary antagonist of Captain Underpants: The First Epic Movie, the primary antagonist being Proffessor Pippy P. Poopypants. He has a long history with two fourth grade students named George and Harold due to their constant pranks, wisecracks, and comic books. Due to the effects of George's 3-D Hypno-Ring, Benjamin's alter ego is Captain Underpants, which he is totally unaware of. 

He and his alter ego are voiced by Ed Helms in the film Captain Underpants: The First Epic Movie and Nat Faxon in the TV series The Epic Tales of Captain Underpants.