Master Hand is a boss in the game Kirby & The Amazing Mirror, along with his counterpart, Crazy Hand. He is a levitating magical hand that performs a variety of complicated and random punches, shoots beams and blasts, and forms a fist to pound or grab Kirby. When working with Crazy Hand, they use joint moves like coming together to smash Kirby.
Master Hand is also a mini-boss in Kirby & The Amazing Mirror. He does very similar attacks to his boss form, but they're much less difficult to avoid, and they don't have as wide of a range. Crazy Hand is not included when fighting Master Hand as a mini-boss. When inhaled, he gives you the Smash Power, which is a rare and powerful ability.
 Other Appearances
 Super Smash Bros. Series
Master Hand was originally a boss in the first Super Smash Bros. game. From then on, he has appeared in all three of the Super Smash Bros. games. In Super Smash Bros. Melee, he was included in the Classic Mode as a boss (Crazy Hand was also included in a high difficulty mode). Master Hand played a decently large role in Super Smash Bros. Brawl during the Subspace Emissary Mode as a boss as well.
Related ThreadsDoes anyone know about the second hand of master hand? - last post by @ Dec 14, 2001
Giga Bowser and Master Hand as playable characters? - last post @ Jul 25, 2005
Play as Master Hand and Crazy Hand at the same time. (Emulator) - last post by @ Sep 14, 2013
Giga bowser has not yet been found but i have found master hand as a playabl;e chaacter :3 - last post by @ Apr 26, 2012
Master Hand and Crazy Hand - last post by @ Jun 4, 2004