1: Staryu. Can't evolve, can't learn Surf.
2: Nidoqueen. Must know Surf.
3: Clefable. Must evolve immediately, must learn 4 TMs that teach special moves.
4: Slowbro. Must be caught as a Slowpoke and must know Rain Dance in order to evolve.
5: Pidgeot. Must not evolve from Pidgey until it single-handedly (single-wingedly?) wipes out Erika's team. Must keep Sand-Attack and Fly permanently.
Just one more! I'm looking forward to this!
Hmm... Nidoqueen learns Cut, Pidgeot learns Fly, Nidoqueen learns Surf, Nidoqueen learns Strength, Clefable learns Flash (not necessary, but whatever), Nidoqueen learns Rock Smash, but nothing learns Waterfall. Looks like I have to give you a Squirtle. This Squirtle can only evolve into Wartortle upon learning Rapid Spin, and can only evolve into Blastoise upon deleting Rapid Spin for Skull Bash. TMs can't be used to bypass the level requirements.