Corey introduced his Pokémon, including Rhyhorn, to Ash Ketchum and his friends. When Mewtwo appeared, Rhyhorn charged towards Mewtwo but Rhyhorn was thrown back by Mewtwo's Psychic. Rhyhorn was later captured by Mewtwo by using the Mewtwo Ball. Rhyhorn was later freed along with the rest of the Pokémon by Ash. Rhyhorn then battled against the Rhyhorn clone.
None of Rhyhorn's moves are known.