What subtitle identifies the first Pokémon animated film, released in Japan in 1998?

The first Pokémon animated film is identified by the subtitle Mewtwo Strikes Back.

Its full English title is Pokémon: The First Movie — Mewtwo Strikes Back. The film centers on Mewtwo, a genetically engineered Pokémon who challenges the ideas of identity, creation, and the relationship between humans and Pokémon.

The movie was first released in Japan on July 18, 1998, and was distributed there by Toho. Its English-language release followed in North America on November 10, 1999, through Warner Bros. Pictures.

The film’s title is often shortened to Pokémon: The First Movie, but Mewtwo Strikes Back is the subtitle that distinguishes it. A computer-animated remake, Pokémon: Mewtwo Strikes Back — Evolution, was released in 2019 and is a separate version of the story.