Adamantine Plating. Any critical hit against the golem becomes a normal hit.

Fire Absorption. Whenever the golem is subjected to fire damage, it takes no damage and instead regains a number of hit points equal to the fire damage dealt.

Immutable Form. The golem is immune to any spell or effect that would alter its form.

Indomitable (3/Day). The golem can reroll a saving throw it fails. It must use the new roll.

Magic Resistance. The golem has advantage on saving throws against spells and other magical effects.

Magic Weapons. The golem's weapon attacks are magical.

Regeneration. The golem regains 10 hit points at the start of each of its turns. If the golem takes damage from a adamantine weapon, this trait doesn’t function at the start of the golem’s next turn. The golem dies only if it starts its turn with 0 hit points and doesn’t regenerate.

Siege Monster. The golem deals double damage to objects and structures.

Multiattack. The golem makes three melee attacks.

Slam. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

Adamantine Sword. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 23 (3d10 + 7) slashing damage.

Poison Breath (Recharge 5-6). The golem exhales poisonous gas in a 15-foot cone. Each creature in that area must make a DC 20 Constitution saving throw, taking 45 (10d8) poison damage on a failed save, or half as much damage on a successful one.