SCYTHER- Give METAL COAT. Evolves into SCIZOR.
ONIX- Give METAL COAT. Evolves into STEELIX.
POLIWAG- Give KING'S ROCK. Evolves into POLITOED.
SLOWPOKE- Give KING'S ROCK. Evolves into SLOWKING.
SEADRA- Give DRAGON'S SCALE. Evolves into KINGDRA.

Remember- You must trade to activate evolution. Give the item prior.