In pokemon black, who do you give the prism scale to make them evolve?

The Prism Scale is an evolution-inducing item that is used to evolve Feebas (#349) into Milotic (#350) if the Pokemon is traded while holding it. In Pokemon Black and White, Prism Scales can be found on Route 13, in Undella Town and obtained by Pokemon, level 51 or higher, with the ability Pickup.