Mewtwo is the central antagonist of Pokémon: The First Movie.
In the film, scientists create Mewtwo from research connected to the Mythical Pokémon Mew. Mewtwo awakens with extraordinary psychic power and becomes angry about being treated as an experiment rather than as an individual.
Team Rocket leader Giovanni initially attempts to use Mewtwo as a weapon. Mewtwo later leaves Giovanni and invites Pokémon trainers to New Island, where it tests its strength against both human trainers and cloned Pokémon.
Mew, the Pokémon linked to Mewtwo’s origin, is not the main villain. Instead, Mew serves as Mewtwo’s counterpart during the film’s climactic conflict. The movie’s story ultimately changes Mewtwo from a straightforward threat into a character questioning identity, free will, and whether origins determine a creature’s worth.