In the Dark Cave near the Blackthorn City entrance.
kingsea is not a pokemon. if you are looking for horsea, seadra or kingdra, catch a horsea in whirl islands, evolve it into seadra, and trade it with a dragon scale
Causes Seadra to evolve into Kingdra when traded
Because it has to be on Pokemon Diamond,pearl or Plainum.
Let's see, we've got Feraligatr, Gyarados, Seadra, Seaking, Poliwrath, Plitoad and maybe Mantine, Tentacruel, Octillery or Quillfish.
Seadra does not evolve into Seaking. Ever. Period.
Seadra will evolve when you trade it while it holds the item Dragon Scale.
Seadra can be evolved into Kingdra by using a water stone
Yes, by trading a Seadra equipped with a dragon scale.
Seadra is #117 in the national pokedex, and it is a Water type Pokemon.
seadra
Seadra can never level up to evolve. You have to trade it when it is holding a Dragon Scale item. - Pokemon Guru
Have your Seadra hold a Dragon Scale, then trade it with a friend. Seadra will then evolve into a Kingdra.