Mew is Pokémon number 151 in the National Pokédex.
Mew was designed as a secret Pokémon for the original Pokémon Red and Green games. It was added late in development and was not normally obtainable through standard gameplay. Its hidden status helped create rumors and encouraged players to discuss unexplained secrets in the games.
The species became publicly known through a CoroCoro Comic promotion in Japan in April 1996. Twenty winners were selected in a lottery and had Mew added to their game cartridges. This unusual distribution helped fuel interest in the games and made Mew one of the franchise’s most mysterious early Pokémon.
Mewtwo is number 150, so the two names and adjacent numbers are often confused. Mew is a Mythical Pokémon associated with the origin of many other Pokémon in the series’ fiction, while Mewtwo is an engineered clone created from Mew’s genetic material. Mew’s official Pokédex number confirms that the original roster contains 151 species, not 150.