Squirtle (/ˈskwɜːrtəl/), known as Zenigame (ゼニガメ) in Japan, is a Pokémon species in Nintendo and Game Freak's Pokémon franchise. It was designed by Atsuko Nishida. Its name was changed from Zenigame to Squirtle during the English localization of the series in order to give it a "clever and descriptive name." In animated appearances, Squirtle is voiced in Japanese by Rikako Aikawa and in English localizations by Eric Stuart, and later Michele Knotz. Squirtle, in the anime, never evolved for reasons never truly explained by the creators.