Make ur friend trade it to u
Cottonee can evolve by means of sun stone, and so can petitil.:)
Cottonee evolves by sun stone. If you have a sun stone you can evolve it at any time.
With a sun stone. a Sun Stone can be obtained in Nimbasa City and Relic Castle.
Black: Cottonee. White: Petilil
You can get a Sun Stone in Nimbassa City. The Sun Stone can be obtained from a person in the apartment left of the Battle Subway on the 2nd floor.
You use a Sun Stone on it.
Evolve a Krokorock with a Sun Stone
You can find a Sun Stone in Raimon/Nimbasa City (The 4th Gym City) The Sun Stone can be obtained from a person in the apartment left of the Battle Subway on the 2nd floor.
Minccino-shiny stone,muna-moon stone,pansear-fire stone,pansage-leafstone,panpour-waterstone,cottonee-sun stone,petlil-sun stone, electrik-thunder stone,lampent-dusk stone
Cottonee does not evolve into Whimsicott at a particular level. You must use a Sun Stone on Cottonee to make it evolve.
Only Cotonnee (black) and Petilil (White) can be evolved using the sun stone in Black and White. However, you can catch Gloom and Sunkern after obtaining the national pokedex, or you can simply relocate from previous generations.
Petilil will evolve with a sun stone, pansage with a leaf stone, panpour with a water stone, and pansear will evolve with a fire stone.