Kevin Hart
George Beard (voice)
Thomas Middleditch
Harold Hutchins (voice)
Ed Helms
Mr. Krupp / Captain Underpants (voice)
Nick Kroll
Professor Poopypants (voice)
Jordan Peele
Melvin (voice)
Kristen Schaal
Edith (voice)
DeeDee Rescher
Ms. Ribble (voice)
Brian Posehn
Mr. Rected (voice)
David Soren
Tommy (voice)
Mel Rodriguez
Mr. Fyde (voice)
Susan Fitzker
Ms. Dayken (voice)
Lynnanne Zager
George's Mom (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)