Fergus introduced his Pokémon, including Tentacruel, to Ash Ketchum and his friends. Tentacruel was later captured by Mewtwo by using the Mewtwo Ball. Tentacruel was later freed along with the rest of the Pokémon by Ash. Tentacruel then battled against the Tentacruel clone.
None of Tentacruel's moves are known.