Undead Nature. The greater zombie doesn’t require air, food, drink, or sleep.   Turn Resistance. The greater zombie has advantage on saving throws against any effect that turns undead.   Undead Fortitude. If damage reduces the greater zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.