Mew

Mew is a Psychic-type Mythical Pokémon from the Kanto region. It is currently only Pokémon of Kanto region that is unavailable to obtain.

Pokédex description
New Species Pokémon

''Mew is said to possess the genetic composition of all Pokémon. It is capable of making itself invisible at will, so it entirely avoids notice even if it approaches people.''

Evolution family
Mew is part of one-member family.

Trivia

 * On August, 2016 Mew's attacks - Hurricane and Moonblast were replaced with Blizzard, which has higher DPS.