Mewtwo! One of the famous legendary Pokemon and one of the most powerful Pokemon in the games and anime.
Mewtwo had a few small cameos in the Pokemon TV show but it wasn't until Pokemon: The First Movie or A.K.A. Mewtwo Strikes Back that Mewtwo's voice was finally heard.
Although Mewtwo can't actually speak its voice can be heard using its psychic powers in the form of telepathy.
Mewtwo, like most Legendary Pokemon, has no official gender, and two Mewtwos have appeared in the anime. In Pokemon: The First Movie, Mewtwo was voiced in the English dub by Jay Goede, credited under the stage name Philip Bartlett. In Mewtwo Returns, it was voiced by Dan Green. In Genesect and the Legend Reborn, a different Mewtwo was voiced by Miriam Pultro. Another Mewtwo appears in the game Detective Pikachu.