Master Hand is the main antagonist of the Super Smash Bros. franchise.
He is a mysterious entity who created the Smash Bros. universe, who makes his home in the Final Destination and seeks to beat all who challenge him. He also appears as the final boss of Classic Mode in every game in the series. Despite always being the final boss, he isn't always a villain, as seen in "The Subspace Emissary" and "The World of Light" story modes.
He was voiced by Jeff Manning in Super Smash Bros., Dean Harrington in Super Smash Bros. Melee, Pat Cashman in Super Smash Bros. Brawl, and Xander Mobus in Super Smash Bros. 4 and Super Smash Bros. Ultimate, all of whom also voice the announcer in their respective games.