his name is Tabuu, in a Mexican site one guy said this dude was from a NES (or SNES) Rare game... did not confirm yet...
Edit: Another asumption
He is a part of the SSE they were attempting to clone people to make warriors for the Ancient minister, but they made a mistake and it created a new person that is not the clone he should be. TABOO : A MISTAKE
And another one:
I've heard around GoNitnendo that he's the body of Master Hand and Crazy Hand.
SSBB FC: 5155 2671 4071 elgefe02: "VGChartz's Resident Raving Rabbit" MKWii:5155-3729-0989