Pokemon!

[zimdoomyday]

Missing No never messed up my game, I think it will only mess up your game if you catch it. the 2 codes go I believe fly to the red Island(it's been so long I don't remember the name) swim up and down the cost until you find Missing no, I think then you run away and when you check your inventory your 6th item will go to x99 there's also another one for the Safari.

Actually it depends on what you name your character. It's really wierd that way. But it will always mess up your Pokemon League, and can do a lot of other stuff including permanently corrupt the cart if you have your name a certain way. I forget how though, but I read about it in a few FAQs (as a programmer, I wanted to know how it works).