Mew debuted in A Glimpse of the Glow. Here, Red and Blue see it in Pallet Town and try to catch it, but fail. It is revealed later on, that Mew inhabits the area near Pallet Town because it lacks the pollution created by humans in other areas.
Team Rocket's chase would continue all the way in The Jynx Jinx, where they attempt to regain the disc containing Mew's habitat and information from Green, but fail and are tricked into stealing an empty one she prepared. They catch up to Green and her unwilling ally Red soon afterward, and interrupt them when they tracked down and attempted to capture the rare Pokémon. However, when their Jynx was able to almost succeed, Mew's powerful Psychic attack left them listless, and soon escaped. The small samples of its DNA that the Rockets acquired, however, led to the creation of its powerful clone.
When Blaine was explaining about Mewtwo's origin to Red, in And Mewtwo Too?! Mew appeared as a silhouette. Mew is later briefly seen looking into Indigo Plateau in A Charizard...and a Champion after Red wins the Pokémon League championship and decides to return to Pallet Town with his two fellow Pokédex Holders.
In Mewtwo and Mew Too, Mr. Briney mentioned that he had recently arrived on Faraway Island and attempted to capture Mew. Once being alerted to his pressence, the New Species Pokémon fled the island and headed for Kanto.
Mew appeared again in Phew for Mew, where it saved Red and the people of Vermilion City from the impending crash of the TR helicopter. Mewtwo notices this, and realizes that he too had a root to trace itself back to, as it was born from Mew's eyelash.
Mew was mentioned in the Emerald chapter, where Mr. Briney had given Ultima soil from Faraway Island, Mew's birthplace. Ultima then instructed Gold to bring it as it will come in handy. When he arrived, he gave to Emerald who used it to calm down the rental Pokémon under Guile's control.
Personality and characteristics
Mew is a curious and playful individual, often stopping to watch events it finds interesting. Mew is also selfless, saving Red and his Pokémon from the TR helicopter's impending crash. It also prefers areas that are untouched of pollution, such as Pallet Town.
It is able use its psychic powers in many ways such as levitating, disturbing air currents telekinetically and emitting an aura around it. Due to possessing the genetic composition of all Pokémon, soil from its birth place, Faraway Island, will calm any Pokémon down, excluding certain Legendary and Mythical Pokémon.