Starmie

Starmie (スターミー Starmie) is a starfish-like /-type Pokémon. It is the evolved form of Staryu. At the center of its body is a red core, which sends mysterious radio signals into the night sky.

Anime
In the anime, Misty owns both Starmie and a Staryu at the same time making it one of the extremely rare cases that trainer has both pre- and post-evolutions on their person at the same time.

Description
Interestingly Starmie's "back-half" has been depicted several different ways. In the anime Starmie has the appearance of two starfish fused together; wile in more modern games the back-half has been shown to spin wildly completely independent of the front-half of the Pokémon. Many fans tend to think of the anime's depiction as the more realistic of the two considering the rapid spinning would obviously get in the way of a trainer trying to surf on this particular Pokémon.

Trivia

 * Despite being Genderless, it was able to learn egg moves in Gold and Silver. It was fixed in Crystal though.
 * Starmie is one of the 3 Pokemon that has no visible eyes. The others are Staryu and Zubat.