Rotting Stench. Decay and rot have ravaged the body of the deceased hill giant, and the high amounts of oily fats stored in their body have decomposed, leaving an unbearable stench. Creatures that can smell within 20 feet of the Zombie Hill Giant must make a DC 12 constitution saving throw or take 1d4+1 necrotic damage at the start of each round. This condition is nullified by holy auras. If the Giant takes radiant damage, it must make a DC 16 con save. On a failure, the stench's strength subsides for 2 rounds. 

Undead Armor. Zombie hill giants often use rope to tie smaller undead together to use as armor. Hill giants usually have up to 15 (3d6+3) zombies or skeletons as armor. The Giant's AC is +1 for every 5 undead they are currently wearing. If the giant would take physical damage from an attack,  it can choose to spread the damage out across its armor. For every 5 damage reduced by this ability, the number of undead worn by the giant is reduced by 1. Damage from critical hits or attacks that are made with advantage cannot be reduced by this effect. Once detached, the undead creatures from the armor are able to take their own actions, using the stat blocks of either basic zombies or skeletons. These undead creatures have 5 HP each. 

Multiattack. The giant takes two attack options or one Greatclub attack and one Grab action.

Greatclub. Versatile Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage (two-handed) or 14 (3d6+7) bludgeoning damage (one-handed).

Zombie Projectile. Ranged Weapon Attack: +10 to hit, range 60/240 ft., one target. Hit: 10 (1d10 + 7) bludgeoning damage. Creatures hit by a thrown zombie or an object of a similar size must make a DC 14 dexterity saving throw or are knocked prone. On a miss, the zombie lands within 5d4 feet of the target, and on a DC 15 constitution save, can attack the player as a reaction if they are in range. 

Grab. A large or smaller creature within 10 feet of the Zombie Hill Giant must make a either a DC 14 DEX saving throw or a DC 14 STR saving throw or is restrained by the Giant. Restrained creatures cannot move and can make a DC 17 STR saving throw to escape as an action. The Giant can't take the multiattack action while holding a restrained creature. 

Bite. Melee Weapon Attack: 1d20+8 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 5) piercing damage. Restrained creatures must make a DC 14 STR or DC 14 DEX saving throw or are swallowed. Swallowed creatures are deafened and blinded. They take 2d8+3 acid damage at the start of each of their turns. Swallowed creatures can make an attack rolls and cast spells while swallowed. If the Zombie Hill Giant takes 20 or more damage, it must succeed on a DC 23 CON saving throw or regurgitates all swallowed creatures. Regurgitated creatures exit the Giant prone. 

Undead Ammunition. As a bonus action, the Zombie Hill Giant can take one zombie or skeleton off of its armor. The giant can then use the zombie or skeleton as ammunition for its Zombie Projectile attack.