The undead glitch is a glitch in Super Smash Bros. Brawl and Super Smash Bros. 4 that allows Giga Bowser, Wario-Man, Giga Mac, Mega Charizard X, or Mega Lucario to survive after being defeated in Stamina mode.
When this occurs, if Giga Bowser, Giga Mac, Mega Charizard X, or Mega Lucario's HP is depleted, their stamina gets reduced to 0 HP (zero hit points). Then they are able to continue to fight; despite having "0 HP" displayed. Being touched by any hitbox even if it deals no damage (a Banana Peel, F.L.U.D.D. from Mario, or Water Gun from Squirtle) or hit by a status move (such as being put asleep or using recovery items which normally recover HP like Food) gets the character KO'd. A 0 HP Giga Bowser, Giga Mac, Mega Charizard X, or Mega Lucario can freely get another Smash Ball to trigger the glitch again.
It is possible that an undead character can win a stamina match if they remain untouched (with 0 HP). However, Wario-Man in Brawl is an exception. In Brawl, Giga Bowser can win a match if he defeats his opponents; but Wario-Man cannot win a match. Because Wario-Man loses his damage meter upon triggering the glitch and counts as being KO'd. The match ends in his defeat; even if he KO's the other players. Instead of Wario-Man winning, the winner becomes the last player who was defeated by Wario-Man's attack. In SSB4, Wario-Man behaves like all other characters.
Characters that can induce the glitch
Ads keep SmashWiki independent and free :)