The Grim Adventures of Billy and Mandy (2001)

Episode Overview

Billy and Mandy inform Grim that it’s “Opposite Day,” where their words mean the opposite of what they say. Struggling to grasp this tricky idea, Grim ends up stuck doing Mandy’s chores. Just when Grim believes he has caught on, interpreting Mandy and Billy's desire for pie as a lack of interest, Mandy throws him a curveball by declaring that their claim of it being Opposite Day was actually false.