What subtitle did the first Pokémon theatrical film use?

The first Pokémon theatrical film used the subtitle “Mewtwo Strikes Back.”

The film was released in Japan in 1998 under the title Pokémon the Movie: Mewtwo Strikes Back. Its story centers on Mewtwo, a genetically engineered Pokémon created from research involving Mew, and its conflict with humans and other Pokémon.

For its English-language theatrical release in 1999, the film was marketed as Pokémon: The First Movie — Mewtwo Strikes Back. It became the first feature film based on the Pokémon franchise and helped turn the anime’s international popularity into a major cinema event.

The title is sometimes shortened to “Mewtwo” in casual conversation, but that is not the complete subtitle. Later films used different subtitles, including The Power of One, which belongs to the second Pokémon movie.