Use a good rod in seafoam islands.
Chat with our AI personalities
You wil have to trade with FireRed or XD.
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.
Pallette Town with the Super Rod. (Yes, you need the Super Rod in Fire Red.)
Shellder is a version exclusive Pokemon only found in Fire red. But, Instead of Shellder, you can get Slowpoke, if you use a good rod in the Vermillion city harbor.