You have to use a Kings Rock to evolve Poliwhirlinto Politoed. You give the Kings Rock to Poliwhirl and trade it with a friend which triggers its evoloution. IMPORTANT: DO NOT EVOLVE INTO POLIWRATH FIRST.
When you use water stone or trade him with king's rock and he evolves into Poliwrath with water stone or into Politoed with king's rock.
Clefairy......
Magmius or honchkrow
eevee
happiny
growlithe & eevee
fire stone
hard stone can be found at dark cave
In Pokemon Gold, Silver, and Crystal, Poliwhirl evolves into a Poliwrath when you use a Water Stone on it. Poliwhirl can also evolve into Politoed if you give it a King's Rock to hold and trade it to another player.
Through an action replay code
onamyte is one
Exeggcute, Weepinbell, Gloom.