To beat the Pokemon Leaf Green version for Gameboy you have to get the Nation Dex and beat Raiku and Suicune.
beat the Pokemon league.
You will only need to beat it if you want to transfer pokemon from the games Ruby, Sapphire, Emerald, Pokemon Colosseum and Pokemon XD Gale of Darkness. You can transfer pokemon immediately to another leafgreen or a firered version using either the GBA link cable or the Wireless Adapters.
Beat the elite four.
i guess nothing
You have to beat the original champion in the game
no but you beat the game you may migrate a mudkip from Pokemon emerald version /leafgreen/firered/Sapphire/and rubie.
y beat brock at pewter Jim
U have to beat the elite four and get the nation dex
The best team to beat elite 4 in Pokemon firered and leafgreen are the first six Pokemon you caught and trained
You can't get that poke'mon in Leafgreen. It is impossible. Trust me. I would know. I know how to beat the whole game.
You have to beat the game then you will be able to go in I bealeave mewtwo is in there
beat the Pokemon league