Stone Camouflage. The giant has advantage on Dexterity (Stealth) checks made to hide in rocky terrain.

Undead Fortitude: If damage reduces the zombie to 0 Hit Points, it must make a Constitution saving throw with a DC of 5+ the overkill damage, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 2d12+8 hit point instead.

Multiattack. The giant makes two greatclub attacks. Greatclub. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 19 (3d8 + 7) bludgeoning damage.

Rock. Ranged Weapon Attack: +10 to hit, range 60/240 ft., one target. Hit: 28 (4d10 + 7) bludgeoning damage. If the target is a creature, it must succeed on a DC 18 Strength saving throw or be knocked prone.

Rock Catching. If a rock or similar object is hurled at the giant, the giant can, with a successful DC 10 Dexterity saving throw, catch the missile and take no bludgeoning damage from it.