Blue Oak is the player's rival in the Generation I games and their remakes, and is a Pokémon Champion. During the Generation II games, Blue serves as the Gym Leader of Viridian City's Gym in the absence of Giovanni. Blue is very unique as a Gym Leader, because he has no set type for his Gym, and instead uses a variety of Pokémon. He gives the Earth Badge to trainers who are able to defeat him.