You wil have to trade with FireRed or XD.
Use a good rod in seafoam islands.
Poliwhirl → Poliwrath, Shellder → Cloyster, Staryu → Starmie and Eevee → Vaporeon
lombrea, evee, poliwhirl, shellder, and staryu. some of these can only be found in firered and leafgreen so you will need to trade. that's all I can think of.
You cant find it in Firered only leafgreen.
I know firered can, if you seen a shellder look at it on your pokedex and check its area if it says unkown you will HAVE to trade a shellder to leafgreen from firered.
a piece of cheese
You wil have to trade with FireRed or XD.
Cloyster can only be obtained through evolving Shellder. Shellder is a FireRed-exclusive Pokemon in Generation III.
Shellder can be found in firered and leafgreen either you fish for one or look in seafoam islands.
Use a good rod in seafoam islands.
You can catch shellder in Pokemon red, blue, yellow, gold, silver, crystal, FireRed, XD, diamond, and pearl.
Poliwhirl → Poliwrath, Shellder → Cloyster, Staryu → Starmie and Eevee → Vaporeon
u hau have to trade a shellder from firered and then evolve it w/ a water stone.
bob
in route 201
lombrea, evee, poliwhirl, shellder, and staryu. some of these can only be found in firered and leafgreen so you will need to trade. that's all I can think of.