Cooties is a horror-comedy that stars Elijah Wood, Rainn Wilson, Allison Pill, Saw/Insidious writer Leigh Whannell, and Glee scribe Ian Brennan as teachers whose prepubescent wards turn into blood-crazed zombie-fiends after eating suspect chicken nuggets. But this latest release from SpectreVision (the horror production company set up by Wood, Daniel Noah, and Josh C. Waller) began life as a much more straight-faced venture.

“We wanted to make a serious movie, that’s the really funny thing,” says Wood. “We wanted to make it this very serious movie about killer children. Leigh was the one who was like, ‘It’s called Cooties, it should be a comedy.'”

Whannell and Brennan co-wrote the script and Jonathan Milott and Cary Murnion directed it. Cooties will open Sept. 18 in theaters and VOD. Check out the film’s trailer and poster below.