1x5 - The Super Mario Bros. Super Show!

Rolling Down the River The Marios and Toad are trying to save Princess from Koopa's riverboat. When their plan goes horribly wrong, Toad gets caught and the Marios barely escape with their lives. The Marios then meet up with Mark Twang, a man who's in a race with Koopa. The Marios and Mark now have to work together to beat Koopa and rescue Princess and Toad. The Mario Monster Mash Mario ends up switching bodies with Dr. Frank N. Stein's dim-witted monster.