De två extremt fantasifulla busungarna George och Harold hypnotiserar sin rektor till att tro att han är en superhjälte som heter Kapten Kalsong.
Kevin Hart
George Beard (voice)
Ed Helms
Mr. Krupp / Captain Underpants (voice)
Thomas Middleditch
Harold Hutchins (voice)
Nick Kroll
Professor Poopypants (voice)
Jordan Peele
Melvin (voice)
Kristen Schaal
Edith (voice)
Dee Dee Rescher
Ms. Ribble (voice)
Brian Posehn
Mr. Rected (voice)
Mel Rodriguez
Mr. Fyde (voice)
David Soren
Tommy (voice)
Susan Fitzker
Mrs. Dayken (voice)
Lynnane Zager
Mrs. Beard (voice)
Tiffany Lauren Bennicke
Sad Girl (voice)
James Ryan
Mime (voice)
Leslie David Baker
Officer McPiggly (voice)
Sugar Lyn Beard
Goodie Two-Shoes Girl (voice)
Lesley Nicol
Nobel Moderator (voice)
Chris Miller
Nobel Audience Member (voice)
Coco Soren
Balloon Girl (voice)
Nicholas Stoller
Manus
Dav Pilkey
Manus
David Soren
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