Twenty people were selected in the 1996 Pokémon Mew lottery.
Mew was a hidden Pokémon added late to Pocket Monsters Red and Green. It could not normally be obtained through ordinary gameplay, which made it mysterious to players and helped generate rumors around the new franchise.
In April 1996, CoroCoro Comic announced a promotion called the Legendary Pokémon Offer. Readers sent in postcards, and 20 entrants were selected at random. The winners sent their game cartridges to be modified so that Mew could be added.
The promotion was an important early marketing success. It increased word of mouth and helped keep interest in the games after launch. Mew's National Pokédex number is 151, but it should not be confused with the original game's 150 routinely obtainable Pokémon or with Mewtwo, which is a separate species.