Sneaky Lying Cheating Giant Ninja Koopas - S1-E2
Character mistake: When Luigi says that the Koopalings will arrive at Prince Hugo's castle at any minute, he can be smiling. (00:02:57)
Toddler Terrors of Time Travel - S1-E8
Character mistake: This series is a continuation of "The Super Mario Bros. Super Show." However, in this episode, King Koopa implies that he has never taken over the Mushroom Kingdom. This contradicts a main plot point of "The Super Mario Bros. Super Show!", where in many episodes, Mario and his friends look for someone or something to help Princess Toadstool free her kingdom from King Koopa, who has taken over her kingdom.
Character mistake: When Luigi is about to jump into the Warp Pipe to Pipe Land, he says Mario told him to wear a Frog Suit, but it was actually Princess Toadstool. Mario repeats this error after Luigi asks if he is all right. (00:06:58 - 00:10:01)
Mush-Rumors - S1-E17
Character mistake: When Bud and Missy are scared when the Chain Chomps are sent out, they appear to be smiling. (00:07:14)
Crimes R Us - S1-E19
Character mistake: When Cheatsy and Kooky are on top of the treasury, its sign misspells it as "tbeasury". In the same shot, Cheatsy's blue hair turns yellow. (00:10:37)
Life's Ruff - S1-E20
Character mistake: When first showing the Florida State Poochitentiary, the white sign in front of it misspells the name as "Florida State Poochitentary." (00:06:41)
7 Continents for 7 Koopas - S1-E22
Character mistake: When Mario and his friends are trying to unclog the pipe, Toad says for the Mario Bros. to pull the plunger, but they are initially pushing it instead. In the same shot, Mario's brown hair turns black. (00:05:57)
7 Continents for 7 Koopas - S1-E22
Character mistake: When King Koopa notices the Koopalings running to him, the screen with Antarctica has its title misspelt as "Antartica." Also, the dragon that appears on the screen for Asia goes from green-yellow to white and blue.
7 Continents for 7 Koopas - S1-E22
Character mistake: When first displaying the screens which have the names of the continents listed underneath them, Antarctica is misspelt as "Antartica."