Rhyhorn is a Pokémon that Corey took to New Island after Corey was invited to meet the "World's Greatest Pokémon Trainer". In an attempt to capture Mewtwo, Corey had his Rhyhorn charge at Mewtwo, however, Mewtwo used its psychic powers to lift Rhyhorn and fire it away from itself. Mewtwo captured Rhyhorn and made a clone of it for himself.