Starmie

Japanese name:	スターミー
Nickname:	Staross

Starmie is a dual-type Water/Psychic Pokémon introduced in Generation I.
It evolves from Staryu when exposed to a Water Stone.

Starmie is a Pokémon that resembles two violet starfish with five appendages each. The front starfish has a golden formation in the center. In the center of the golden casing is its red jewel core, which can glow in seven colors and has developed to resemble a cut precious stone. The second starfish is semi-attached to the back of the first and can spin 360 degrees. This rotational action is how Starmie swims through the ocean. It can also launch itself out of the water and fly through the air for short periods, as seen in Pokémon Snap.
From its core, Starmie can emit electrical waves that are powerful enough to reach the furthest parts of the universe. The multi-color glowing of its core is also believed to be a method of communication inside the species. As seen in the anime, the core will go dark if Starmie is knocked unconscious and will sometimes flicker if Starmie is low on health. Because of its body shape and habit of sending transmissions skyward, some people believe this Pokémon to be extraterrestrial. Being the result of an evolution via Evolution stone, Starmie is rarely seen in the wild, but it can be found in the deepest parts of the ocean. Starmine preys on the tiny plankton by absorbing it while cursing the ocean. It is Lumineon's favorite food.

Bulbapedia