Creepiest Glitches in Nintendo Games
There is a good reason why companies have players test their games: to look for glitches. Glitches can be either minor or major. Some people may like glitches and think they are interesting, but it might not be the same story for others. Some may just do things like crash your game, and others may softlock your game. Thankfully, some glitches get patched.Nintendo is quite familiar with glitches. There are many infamous glitches that this company has, or had. Some can be just shrugged off like they are nothing. However, some can, well, leave you unsettled after your experience with them.

This happens when one fighter's moveset is given to another fighter. For example, giving Pikachu Fox McCloud's moveset can cause Pikachu to look... off. Its legs are longer, and its arms are, too. This could have also been done with others. Each, well, "experiment" had different results.
Shortly after the release of Super Smash Bros. for Wii U, a player reported something similar. All fighters were deformed, yet had their regular movesets. This is definitely interesting. Hopefully this will not happen in Ultimate!

For those who don't know, Missingno, or "Missing Number", was a glitch in Pokemon Red and Blue that could duplicate items and do other stuff. Attempting to use Missingno in battle can softlock the game if it gets hit by an attack. However you can fix this by reloading the game (not totally resetting). You can catch Missingno. by watching the old man's demonstration on how to catch a Pokemon, then fly to Cinnabar Island then surf up and down the east coast. Missingno. has been associated with many creepypastas. At least, that's what I heard from Top15s or another youtuber.

I've seen it before, but I have NO idea how to do it. Well, I'll at least explain what it looks like. Basically, if you do the glitch, Pikachu would look like Boba Fett from Star Wars.
Go to Wet Dry World, set yourself on fire and hit a star box right before you run out of health. If you did it right, well...HAVE FUN.
Imagine listening to that music over and over until you run out of lives from the timer...
or you can just reset or something

Search it up on Google Images. I dare you.
This one is creepy
If the player and the helper are using the Hammer or Parasol abilities (can have one player be hammer and the other be parasol or both players can have the same ability) (also can be done with a CPU controlling the helper), there is a very slim chance of randomly teleporting to a glitched Marx battle. Winning this battle will still count as beating Milky Way Wishes, even if it has not yet been unlocked. I got this information from wikirby.com.
Holy moly that is creepy
For those who don't know, Pac-Man was made in 1980. Games back then had no ending, they just were meant to continue until the player lost. However, due to a bug in the code, Level 256 is corrupted on the right side with random symbols. This makes it impossible to beat the level, since the aforementioned symbols overwrite the values of the dots on that side.
I don't think Pac-Man is a nintendo game...?