Mewtwo

Pokemon Games
Mewtwo appeared in Blue,Yellow,Red,LeafGreen & FireRed in other games Mewtwo had to be migrated,such as Ruby,Saphire,Emerald,Gold Silver,Diamond or Pearl version.Mewtwo also appeared in the Smash hit Super Smash Bros. Melee and other games like,Pokemon:XD Gale of Darkness,Pokemon Colesseim,and Mewtwo might be in the new smash hit game,Super Smash Bros. Brawl since he made an appearence in Super Smash Bros. Melee.

Smash Bros.
Mewtwo appeared as the strongest character to be unlocked by 200vs.matches or 20vs. hours.