How do you get MissingNo on Pokemon FireRed and LeafGreen?

Answer 1

Disregard all previous answers, as they were wrong and had numerous grammatical errors.

There is no "Sure" way to encounter "MissingNo." on Leafgreen OR Firered, it was a pokemon on Red and Blue (For gameboy colour) to compensate for a glitch which led to a pokemon being obtained with a higher number than the cap of 151. If however you wish to try, follow the same steps as the previous games, Fire Red and Leaf Green were revised and all glitches were said to be taken out.
It is a rather long explanation but it can be found on Gamewinners.com

Answer 2

You can't with out a GameShark they took missingNo out before yellow came out, but in yellow there still is glitches like missingNo but only in red and blue can you catch the original missingNo.

Answer 3

The true answerin order to get the all powerful(if not somewhat dangerous)MissingNo please follow these steps:

Items and conditions needed: a Gameshark, the rainbow pass, a pokeball, and a ditto.

Step 1) in the gameshark actvate the following codes: Wild PKMN easy catch, Free daycare, and Quik level gain(daycare). now find a trainer you have not battled yet and thow a pokeball at their Pokemon(don't worry it will work). now when you go to your party their will be a Bad EGG. do NOT try to hatch it instead go to the daycare and put in ditto and a Pokemon you do not want.(the Pokemon will be killed) come back later and talk to the old man and he will say "your ditto and bad egg are doing fine." then talk to the old lady inside and take Bad EGG LV 100. then look at its summary. it will show a picture of MissingNo.

WARNING!!!: release it emeadiatly if you value your life!!!!!!!!

Answer 4

You need to have a messed up game, and if the Missingno comes, it'll have Pokerus, but that's good, so don't freak out.

Answer 5

Don't try to find it it will ruin your game!

Answer 6

Unless you want to waste money, don't.