Okay, heres the truth about Missingno., and the whole debate about how it's levels and what Pokemon appearing with missingno happen.
Firstly, the idea that the Pokemon you encounter on the east side of Cinnabar are dependant on the Pokemon you encounter elsewhere is mainly false. Although there is no way to prove it is false, the real truth is that the Pokemon you encounter there, as well as their levels are dependant on your players NAME. I've read on other websites that the 2nd, 4th, and 6th characters in your name determine level, while the 3rd, 5th, and 7th determine the pokemon. There is a lot of evidence to support this and from what I've seen this conclusion was made after a LOT of experimenting.
Although it's hard to remember, if the second character in your player name is a question mark, and your third is a lower case q, you will encounter a level 245 Mewtwo at cinnabar.... the reason the name affects the Pokemon is because the characters in your name are made up of hex codes, which are also shared by every Pokemon in the game. Each character in your name holds a value equal to the value of a pokemon.
Im sure if you use a search engine you will find a list of what names create what pokemon.
Added by: skaterava Jan 6th 2008, ID#4789