From SmashWiki, the Super Smash Bros. wiki
Mewtwo2000 is smasher who usually mods Super Smash Bros Brawl and Project M. He likes Mewtwo and tends to play as it in Project M. Before Mewtwo was added to the Project M roster, he used Lucario and put a Mewtwo skin over it. He usually plays casually, but sometimes plays competitively, though he is not too good at it. He was a member of the Project M Back Room before it disbanded. He is known for making some of the most well known hacked stages. He has made a lot of past stages in the Smash series such as Dream Land and makes unique stages as well. He will also showcase other hacks that aren't even made by him.