They say that there is an entity lurking around on some personalized copies of Super Mario 64. They first caught a glimpse of it during Nintendo's E3 panel in 1996, but it was largely ignored. You will get to see it, but there is a ritual involved.
What you need:
A Nintendo 64 console with one controller
A copy of Super Mario 64
Instructions:
1.Start on a new game. If you already have progress, skip to step 3.
2.Play until you get 30 stars. This will unlock the room where the Apparition lives.
3.Wish with all your heart that Mario is not alone and that there are more characters. Or something like that.
4.Keep wishing until you go through the 30-star door. If your controller stops working and the music slows down, it means your wish has been sent throughout the universe and someone heard it on the other end.
5.An image of Wario's head should fade in through the portal where Dire, Dire Docks is located. Depending on the personalization you have, Wario should look different. All the versions of Wario have one thing in common: A higher poly count than usual, something like Andross or Bowser would have.
6.It is most recommended that the moment you see Wario, you should turn the game off as fast as you can. If so, skip to step 8. If you wait any longer, Wario will say, "You want fun? Wario show you fun!" The theme for the Endless Stairway begins to play and Wario will start flying towards Mario at incredible speed. You'd expect at this point that Mario would run to the door, go through, and that would be it, right? Sadly, no.
7.Where the door should've been is now an endless hallway, making Mario run endlessly. Unfortunately, Wario is much faster, and he will catch Mario within 15 seconds, unless you turn the game off before he does. The creepy ascending xylophone music gets faster as the giant laughing head closes in.
8.Should you turn the game off, the moment you return to the game, everything will be back to normal. The ritual has worked and is now complete. If you reset the game, Wario will still chase you.
Several people have tried this ritual through the 90's, and those who let Wario catch Mario... Well, nobody knows what happened.