The "communications terminated" error screen in Super Mario 64 DS and New Super Mario Bros. is uncharacteristically startling, interrupting gameplay with a red error screen and loud siren.

In Super Mario RPG, refusing to give the Baby Yoshi cookies after talking to him in the middle of a jump will cause Yoshi to completely freeze. His only motion will be sliding silently along the ground.

It is possible to break the Frog Flap microgame in WarioWare simply by being too skillful. Red platforms speed up the frog, blue ones slow it down. By skipping red platforms and landing on the blue ones, the frog will eventually start flying and never come back down.

In Super Mario Galaxy 2, the Wigglers on the Tall Trunk Galaxy slide are special slide-only Wigglers that literally cannot exist outside of it. If one of them is allowed to make it all the way up the slide, he will lose his head and become a singularity.

In Super Mario Sunshine, there is a small plant in Gelato Beach that raises a staircase when sprayed with water. In the files, an unused, presumably corrupt animation for it exists that shows it slowly stretching in an unsettling manner.

In Super Mario Odyssey, there is a single Luigi who is somehow too much for the Nintendo Switch to handle. Bringing the camera close to this 8-bit Luigi in Metro Kingdom at night will cause the game to stutter and slow down to 5 FPS. This is the only Luigi who has this effect.

Mario & Luigi: Partners in Time contains an unused enemy called the Scoot Bloop, a Blooper whimsically wearing shoes. It has two attacks: a regular one and a "do nothing forever" attack where it just freezes in place and refuses to end its turn, trapping the player indefinitely.

Using a specific setup in Super Mario Maker 2, it is possible to create a "Negative Space Koopa Troopa". It will not only be invisible, but make objects behind it invisible as well, appearing as a walking hole in reality.