Nightmare Fuel / The Adventures of Super Mario Bros. 3

Even though The Adventures of Super Mario Bros. 3 may be the most faithful animated adaptation of Mario Bros., even the show can sometimes get a little too frightening.

General

• Cheatsy's appearance may get to some, with his squinted, shifty, stoner-like eyes. His plans tended to be very competent, too.
• With the way he treats his siblings, Bully Koopa counts for those who grew up with a Big Brother Bully. Next to Cheatsy, his plans tended to be the most fearsome.
• Kooky's psychotic Laughing Mad demeanor.
• The Piranha Plants and Nipper Plants look terrifying.
• The Ice Land remix that plays in the show is scary in of itself. Hell, quite a few of the remixes in the show are terrifying.
• While King Koopa is a dastardly villain, there are some parts of the show that prove Mario and his friends aren't afraid to give him a taste of his own medicine either, with some of these reprisals being surprisingly cruel in retrospect. In "Do the Koopa", they steal the Doom Dancer Music Box with the intent of making him dance until he dies, and in "Oh, Brother," after Kooky's own mind control helmet falls on him, they command him to chase after his own father, with full intent to "smash, crush, pound, DESTROY!"

Specific

• The Boos taking over the Mushroom Shopping Mall in "Reign Storm" with the Mushroomers fleeing in terror. One Boo even flies toward the camera.
• Madzilla going on a rampage in "Dadzilla", not helped by a crowd of people infuriating it when they throw things at him.
  • Also there's Madzilla's mother. Yes, she was built by the Marios but no wonder Kootie Pie and Big Mouth wanted to get back home so badly.
• "Misadventures in Babysitting" has the scene where the Koopa Kids throw Junior in the pipe maze. In the maze, he is ambushed by Thwomps, frightened by Boos and nearly gets burned alive by lava.
  • Luigi's face when scaring the Boos, while a CMoA, is still pretty terrifying.
• In "Do the Koopa", Koopa plans to make the whole Mushroom Kingdom dance until they're dead by way of the Doom Dancer music box—whoever hears it cannot stop dancing. Thank goodness Luigi had that plumbers' putty.
• Virtually everything that happens to that poor family from "Mush-Rumors". Their car crashes and nearly gets totaled in an unfamiliar fantasy land, everyone accuses them of being aliens and the Koopas shoot Bob-ombs at them before abducting them in the Doomship. To top it off, Kooky hooks them up to a machine to analyze their brains. Surreal and disturbing just doesn't begin to describe the experience.
• Mario's near-drowning in "The Ugly Mermaid", complete with the aforementioned scary version of the Ice Land theme. This even scares him to the point where he won't go in the water.
• Mario turning the Great Wall of China into a dragon in "7 Continents for 7 Koopas". Yes, Bully spraying graffiti on the wall was wrong, but it's practically harmless compared to what Mario did to it, though it seems most likely that he only did it temporarily to give Bully a rather successful scare.
• "Recycled Koopa":
  • The Koopas littering all over Brooklyn would be annoying but nothing too serious if it weren't for the fact that said garbage also causes the New Yorkers to turn into Koopa Zombies. A process which only takes a few seconds. The bros try to get help from city hall, only for them to find they got there too late. Less than a day later, Koopa explicitly stated he'd taken over all of Brooklyn and plans to move on to the other boroughs. If it wasn't for Luigi, there would have been no one left to stop him.
  • If one thinks the effects of the evil garbage are restricted to humans, they're not; as shown when the wildlife also gets exposed to the garbage and turns into minions such as Paragoombas and Cheep Cheeps.
  • After learning about what his rubbish had done, Koopa doesn't waste any time and orders the zombies to kill Mario and Luigi and gives them plenty of weapons to help them out, forcing the brothers to flee for their lives all over the city.
  • Just when the bros manage to escape the zombies and think they're safe, Mario also starts to slowly turn into a koopa zombie. Despite lasting longer than most victims, it's not long before he succumbs and also tries to kill Luigi. The whole thing gets extra creepy with Mario's last line, which all but explicitly states the victims were fully aware of what was happening to them, but couldn't do anything to stop it.
    Mario: You gotta take charge, Luigi. I'm fading fast... Koopa! Koopa!
• King Koopa's plan to eliminate the Mario Bros. in "The Venice Menace" is pretty damn morbid. He has Cheep Cheeps gnaw apart the boardwalk holding up their hotel, which causes it to sink into the water. Following that, he has both a Boom Boom ambush them at their door, as well as having a Sledge Brother bust open their window. Coupled with the fact that they aren't wearing their Frog Suits, King Koopa is subjecting them to either die from the two-way ambush, or drown trying to escape.

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