Psyduck was one of 151 different designs conceived by Game Freak's character development team and finalized by Ken Sugimori for the first generation of Pocket Monsters games "Red" and "Green", which were localized outside Japan as "Pokémon Red" and "Blue". Originally called "Koduck" in Japanese, Nintendo decided to give the various Pokémon species "clever and descriptive names" related to their appearance or features when translating the game for western audiences as a means to make the characters more relatable to American children. As a result, they were renamed "Psyduck", a combination of the words "psychic" and "duck".