You know, regarding creepypasta stuff, sometimes reality is stranger than fiction. The fact that you can come upon this sort of thing accidentally is what really adds to it. It's like you're messing around with the game and you get mysteriously punished for messing around where you shouldn't. I've definitely felt that messing around with gamesharks and things. I bet it's a pretty common experience among especially young people who do stuff like that.
Even though I know all about Missingno and have even seen this before in RU-vid videos, it did kinda freak me out with the one note battle theme, renaming to OLD AMBER, sudden mob walking and becoming a level 1 Rhydon