Mewtwo (Japanese: ミュウツー Mewtwo) is a Psychic-type legendary Pokémon introduced in Generation I. It is among the most well-known Pokémon, being the star of the first movie, and in Generation I, the most powerful Pokémon in regards to its total base stats.
It is not known to evolve to or from any other Pokémon.
Mewtwo is one of the first Pokémon created by science. The scientists who created it dreamed of creating the world's strongest Pokémon. It is widely considered to be unique, due to the fact that only one was genetically created. However, this has yet to be fully confirmed.
Mewtwo is a creature with a humanoid posture, but has a few feline features. Mewtwo's body is grayish-purple with a purple underside and a long, purple tail. Mewtwo has three circular digits on each appendage. It has purple eyes (some times blue when attacking) and two short ears.
One of Mewtwo's most notable features is the tube extending from the back of its skull to its spine. It is most likely a secondary spinal cord, or a system of nerves, allowing for an increased amount of blood and sensory transmission to the brain, heightening its psychic powers.
Due to its early visions of the human race, Mewtwo is known to be very aggressive and thinks of nothing but battling and defeating its foes. Its viciousness results from the repeated recombining of its DNA and the loss of its friend Amber (about whom it completely forgot while sleeping from tranquilizers after meeting her). During the anime special Mewtwo Returns, however, Mewtwo seems to have developed a very protective and guardian-like nature to the point of surrendering to Giovanni just to keep its fellow clones safe.
Mewtwo appears after the Heroes follow Mew to Spear Pillar. Ash has an epic battle with him, but Ash looses, and the Hypnotized Arceus appears from the Hall of Origin, Mewtwo is forced to join the heroes, and Mew joins too. After an intense fight and Pokemon battle, Arceus breaks the mind-control and joins, the Heroes continue their quest.