Mewtwo is the main antagonist of Pokémon: The First Movie. The film presents Mewtwo as a cloned and enhanced Pokémon seeking answers about its identity and purpose.
In the story, scientists create Mewtwo from genetic material associated with Mew. Team Rocket leader Giovanni then attempts to use Mewtwo as a weapon. Mewtwo eventually rejects human control, establishes a base on New Island, and invites trainers to prove the superiority of cloned Pokémon.
Mew is also important to the film, but it is not the main antagonist. Mewtwo’s conflict with Mew drives the central battle, while Ash’s actions lead Mewtwo to reconsider judging beings solely by their origins. Mewtwo later appeared in many games, anime episodes, and films, including the 2019 remake Pokémon: Mewtwo Strikes Back—Evolution.