pokemon leafgreen

Go to mt moon and find clefairy use theif or covet on it. It will take a while because clefairy are rare and one holding a moon stone is really hard to find. Good luck though

PS moon stones can be found at rocket hideouts and on two island as well

You can find moonstones in several locations in the game. You can find one Moonstone in an area in Mount. Moon, and you can find another moonstone in the first area of the burnt out mansion on Cinnabar Island. You can also find Jigglypuff holding moonstones sometimes. You can also find moonstones in another game, have a Pokemon hold them, and then trade them to your game. Hope this helps.

what is the code?

You can easily find five moon stones. There are five normally with a extra chance of getting it with a Pokemon.(I remember I had Nidoking, Nidoqueen, Wigglytuff and Clefable in my 'moon' team ^.^).

1.Mt. Moon (First floor, upper left corner.)

2.Mt. Moon (Yes, there is another one at the end. Between place where you fight one member of Team Rocket and Super Nerd -where you have to chose one of two fossils- There is a rock in bottem right corner)

3.Team Rocket Base (Don't ask me. It isn't hidden, so don't joke you haven't found it. ^.~)

4.Mansion on Cinnibar Island (Go left and up, where is group of rocks. Check rocks. I think third from the bottom contains moon stone, but you must check it yourself ;P)

5.Two Island (After you rescue Lostelle from Hypno, and talk to her father, he will give you moon stone)

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6. There is only 5% chance that wild Clefairy will hold it. So you can try catching it, but this is really rare Pokemon, so I think you have 1% chance to get moonstone from them.
Good luck.