Complete the national pokedex. if you've done that, get all five trainer stars. if you've done that... I applaud you for accomplishing a feat that takes more than just a obssession w/ pkmn, but to make it your life...
Play Pokemon.
if you have the game
you can go to the Pokemon daycare, and leave a compatible male & female Pokemon with them. or, you can leave a ditto and any other Pokemon except a legendary. the only legendary that can breed is rotom
No only in ruby and sapphire and emerald just trade one from those games to leafgreen and now you have it.
i dont now about a trainer but you can cathch it at mt moon
no now shhh im trying to get to sleep
as of right now in present time its impossible you need cheats.
Dive is not an HM in leafgreen however some Pokemon can learn it on there own, if you want to have a Pokemon with dive have the Pokemon that you want learn dive in ruby or sapphire or emerald then have them trade you it and now you can use dive but not outside of battle because its not an HM.
Dive is not an HM in Pokemon firered or leafgreen however if you trade a Pokemon that knows dive from ruby or sapphire or emerald now you have a Pokemon that knows dive But you can't dive underwater in firered or leafgreen because it wasn't invented in the kanto region.
You can get Gold, Silver and Crystal Pokemon by trading them with either FireRed or LeafGreen, then trade those Pokemon in FireRed and LeafGreen with your Emerald. Or after you've defeated the League go to the Safari Zone and the area that was blocked off, can now be explored, it has Johto Pokemon to a certain extent.
You need a cable and go and trade machoke in other gba with any Pokemon It will evolve Now take back the machamp!!!!!!!!
Mew was distributed at an event once, but that is long over and sadly if you want a mew in leafgreen now, you'll need help from other games or you could use cheat codes.