The Super Mario Bros. Super Show!

20,000 Koopas Under the Sea (1x26)

: 17, 1989

When a sea monster attacks the town of Happy Harbor, Koopa offers to stop the monster if the citizens make him their king. Mario and Co work with the fearless Captain Abidab to get rid of the monster themselves, but Mario, Luigi and Princess get swallowed by the monster, which is actually a submarine of Koopa's.