E.V.O.: Search for Eden Cheats

SNES Cheats

Human body

After becoming a mammal, evolve the cat jaws and rabbit body. Then, select the Ramopithecus body. It will become human after two more evolutions.

Mermaid body

Accumulate 10,000 evolution points by the final ocean stage of Chapter 5. Select "Hand and Feet" when evolving your character, then select the "Try To Evolve option". Continue to evolve three times to become a Mermaid.