In Pokémon: The First Movie, Mewtwo is created as a clone of Mew.
The film presents Mewtwo as the result of scientific experiments using Mew’s genetic material. Unlike Mew, Mewtwo is engineered to be extraordinarily powerful and is initially driven by anger toward the humans who created and exploited it.
Mewtwo’s origin is a major part of the film’s conflict, but the character is not simply another version of Mew. The movie contrasts Mew’s natural existence with Mewtwo’s artificial creation, raising questions about identity, purpose, and whether a creature’s origins determine its worth.
The film was released in Japan in 1998 and internationally under the title Pokémon: The First Movie. Its story helped make Mewtwo one of the most recognizable Pokémon from the original generation.