From the Un-Mario Wiki, the Mario no-ledge-base.
“ HAHAHAHAHA!”
—Master Hand
Master Hand is a giant right hand. He was created by
Evil Guy when he accidently cloned
New Mario's hands. Master Hand was then accidently destroyed by New Mario
in an incident that involved 5 cupcakes, a laser, and a breakdancing competition. They were pretty useless, even though they were really strong. He once met
Kirby (Kirby ate Master Hand but crapped him out later) and
Dark Meta Knight.