Mewtwo

Mewtwo is a playable character in Super Smash Bros. Melee. In the Pokémon series Mewtwo is an artificial Legendary Pokémon based on the genetic code of the Legendary Pokémon Mew. Due to constant experimentation, it went out of control and escaped. Mewtwo is commonly called the "Dark Side of Pokémon", which makes it one of the three evil playable characters in Melee. The other two are Bowser and Ganondorf, of the Mario series and The Legend of Zelda series, respectively.

Super Smash Bros. Series
Mewtwo was meant to be a playable character in Super Smash Bros., but time constraints posed as an issue, so it was left out.

In Super Smash Bros. Melee Mewtwo is an unlockable character. Mewtwo appears after the player has played a total of 20 hours in VS matches and then battles the match's winner. If the player defeats Mewtwo, then it is unlocked.

Mewtwo is a somewhat heavy character, but has a high air jump (judging that its a Psychic Pokémon). Its attacks are powerful, but it is not very fast. It also floats above the ground, making it an easy target to be sent flying, and has low traction. Although these attributes make it difficult to control, it is incredibly powerful once used right.

Mewtwo does not use its hands to hold items, but uses telekinetic powers instead, making the items hover before it. A similar style is seen when Mewtwo hangs on a cliff or grabs another character. The only time it does touch an item is when floating on the Parasol. Mewtwo was voiced by Masachika Ichimura in both English and Japanese.

Mewtwo does not return in Super Smash Bros. Brawl as a playable character, but instead has been relegated to the position of just a trophy. It is possible he was replaced with Lucario.

Trophy Information from Super Smash Bros. Brawl
''A Genetic Pokémon. This legendary Pokémon was based on a recombination of Mew's DNA, created by a scientist after years of research. However, Mewtwo greatly differs from Mew in both size and personality and is said to be the most twisted and savage Pokémon ever. Mewtwo has incredibly high combat abilities and uses Psychic-type attacks.''