SpongeBob SquarePants S04 E09 Mermaid Man & Barnacle Boy VI - The Motion Picture

"Be there and be square!"

The adventures of Mermaid Man and Barnacle Boy are being told in a thrilling new motion picture. But after SpongeBob learns the heroes will be played by young actors, he sets out to make his own version of the movie using the real guys, fresh from their retirement home.