Undead Fortitude. If damage reduces the 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.

Turn Resistance. This creature has advantage on saving throws against effects that would turn undead.

Multiattack. The giant makes two greatclub or slam attacks.

Greatclub. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage.

Slam. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage.

Rock. Ranged Weapon Attack: +8 to hit, range 60/240 ft., one target. Hit: 21 (3d10 + 5) bludgeoning damage.

Wide Swing. Special Melee Weapon Attack: The zombie giant makes a wide, low swing trying to hit as many things in front of it with one motion as it can. Each creature within a 10 foot cone in front of the hill giant must make a DC16 DEX saving throw. Each creature takes 18 (3d8 + 5) bludgeoning damage on a failed save. Creatures of medium and smaller size take no damage on a successful save, being able to duck under the swinging club, while creatures of large size or larger take half damage on a successful save.

Alternatively, a creature of large or larger size can attempt a DC18 STR saving throw against this attack to attempt to stop the club. On a failed save, they and each other creature in the area takes damage as normal. On a successful save, only that creature takes half damage, and the hill giant's greatclub is caught, becoming grappled by the successful creature. If the creature succeeds, they may make an immediate opposed STR(Athletics) check to attempt to disarm the giant, or may choose to immediately close any distance between themselves and the giant and grapple it rather than just its weapon.