Dylan Minnette
Zach
Jack Black
Stine / Slappy / Invisible Boy (voice)
Odeya Rush
Hannah
Ryan Lee
Champ
Amy Ryan
Gale
Jillian Bell
Lorraine
Halston Sage
Taylor
Steven Krueger
Davidson
Keith Arthur Bolden
Principal Garrison
Amanda Lund
Officer Brooks
Timothy Simons
Officer Stevens
Ken Marino
Coach Carr
Karan Soni
Mr. Rooney
R.L. Stine
Hallway Player
Caleb Emery
Dumb Jock
Gabriela Hernandez
Screaming Girl
Nate Andrade
Monster
Sheldon Brown
Monster
Melissa Brewer
Monster
Marshall Choka
Monster
Melissa Cowan
Monster
John Deifer
Monster
Everett Dixon
Monster
Brian Gabriel
Monster
Kevin Galbraith
Monster
Maryanne Gorka
Monster
Clare Halstead
Monster
Devin Hampton
Monster
Rory Healy
Monster
Drew Lamkins
Monster
Vivian Kyle
Monster
Charlie Leach
Monster
Katie Lumpkin
Monster
Larry Mainland
Monster
Lucky Mangione
Monster
Justin Natic
Monster
Josh Phillips
Monster
Mickie Pollock
Monster
Steve Quinn
Monster
Ashleigh Jo Sizemore
Monster
Jeff Tenney
Monster
Jennifer Trudrung
Monster
Ashton Lee Woolen
Monster
Coleman Youmans
Monster
E. Roger Mitchell
Mayor (uncredited)
Jason Davis
Cyclist (uncredited)
Ella Wahlestedt
Anna (uncredited)
Amber Thrower
Goth Woman (uncredited)