Codename: Kids Next Door Season 4 Episode 22
Numbuh 1 is sent to retrieve an important code from Rainbow Monkey Island, but after a run-in with the Delightful Children From Down the Lane, he is left stranded there. Soon, he ends up forgetting who he is and starts behaving like a wild Rainbow Monkey. His teammates become very worried when it appears that there may be no way to cure him.
Serie: Codename: Kids Next Door
Episode Title: Operation: F.E.R.A.L.
Air Date: 2005-07-22