The Fairly OddParents (2001)

S2E7 Timvisible

Timmy's chance at winning the perfect attendance award is jeopardized by the school bully, Francis. In an attempt to escape his troubles, Timmy wishes to become invisible, but this leads to chaos as his classmates start to think the school is haunted. The only one unconvinced is Mr. Crocker, who is determined to capture Timmy, believing this will be the proof he needs to confirm the existence of fairies.