Multiattack

The giant attacks twice with its greatclub.

Greatclub

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage. If the target is a Medium or smaller creature it makes a DC 16 Strength saving throw falling prone on a failure.

Rock

Ranged Weapon Attack: +8 to hit, range 60/240 ft., one target. Hit: 26 (6d6 + 5) bludgeoning damage. If the target is a Medium or smaller creature it makes a DC 16 Strength saving throw falling prone on a failure. In lieu of a rock the giant can throw a grappled Medium or smaller creature up to 30 feet. On a hit the target and the thrown creature both take 15 (3d6 + 5) bludgeoning damage. On a miss only the thrown creature takes the damage. The thrown creature falls prone in an unoccupied space 5 feet from the target.

Greatclub Sweep (1/Day, While Bloodied)

Each creature within 10 feet makes a DC 16 Dexterity saving throw. On a failure a creature takes 18 (3d8 + 5) bludgeoning damage is pushed 10 feet away from the giant and falls prone.