Love 'Em and Leave 'Em - S1-E8
Continuity mistake: When Queen Rotunda says she will never find the perfect desert for Prince Pompadour, the yellow trims on her dress turn blue. This also happens when she says that Mario's ice cream looks delicious. (00:08:19 - 00:09:05)
Continuity mistake: When the Mario Bros. pass King Koopa's minions after surviving the first trap, the lenses on Mouser's glasses disappear. (00:11:49)
Love 'Em and Leave 'Em - S1-E8
Revealing mistake: After Luigi pours the love potion, Mario's arms are missing for a few frames. (00:15:45)
Love 'Em and Leave 'Em - S1-E8
Continuity mistake: When Mario runs over to help Queen Rotunda, he has his cap on, but in the next shot, it disappears. (00:09:29)
Love 'Em and Leave 'Em - S1-E8
Continuity mistake: Throughout the episode, the number of fingers Queen Rotunda has on each hand switches between four and five several times.
The Great Gladiator Gig - S1-E6
Continuity mistake: When King Koopa falls into the arena, the rings around his shell's spikes are colored orange, like the spikes, instead of green. (00:15:49)
The Great Gladiator Gig - S1-E6
Continuity mistake: When Tryclydius says that he does not know why King Koopa has to tell him three times for him to understand, his red eyelids turn white like his eyes. (00:04:57)
The Great Gladiator Gig - S1-E6
Continuity mistake: When Toad reconsiders being called a creature, his red vest turns white, like his cap. (00:06:48)
Continuity mistake: After Mario and Luigi pick up their weapons, they can still be seen on the ground. (00:11:39)
Mario meets Koop-Zilla - S1-E28
Revealing mistake: In the live action segment, when Madam AGoGo begins reading the Bros' fortune, a lightbulb can be seen making the crystal ball glow. (00:17:25)
Revealing mistake: When Mario and his friends laugh at the end of the episode, Mario appears to be standing in midair. (00:16:54)
Continuity mistake: When Mario says that Karate Koopa is finished, he is not holding anything, but in the next shot, he has his staff. (00:15:41)
Revealing mistake: When Karate Koopa catches Princess Toadstool and Toad trying to escape, his legs and part of Princess Toadstool's dress are cut off for a few frames. (00:13:49)
Revealing mistake: When Mario and his friends kick the Ninjis when being surrounded by them, one freezes in midair while another duplicates itself. (00:12:48)
Continuity mistake: When Luigi swings his nunchucks a second time, his sideburns disappear. (00:12:40)
Other mistake: When Luigi takes the washer from Misaki, his hand is behind it, but he is still able to get it. (00:07:49)
Continuity mistake: When Misaki says that fear never enters the vocabulary of someone training to be a martial arts expert, Mario and Luigi's gloves disappear. This also happens when Misaki says he will award them black belts. (00:06:24 - 00:16:23)
Mario meets Koop-Zilla - S1-E28
Other mistake: When Luigi asks how he and Mario are going to escape Koop-zilla, the strap on his goggles is missing, and shortly after, they completely disappear. (00:10:02)
Mario meets Koop-Zilla - S1-E28
Continuity mistake: When Mario walks over to Koop-zilla after he throws him a second time, buttons appear on the back of his overalls. (00:13:07)
Mario meets Koop-Zilla - S1-E28
Continuity mistake: When Toad says it is not an earthquake, he is to the left of Luigi, but in the next shot, he is to the right. In the same shot, when he says it was from Koop-zilla, he speaks through Koop-zilla's mouth. (00:04:12)