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.

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

Magic Adamantine Weapons. The golem's attacks are magical. Additionally it's attacks are adamantine weapons, therefore when the golem hits an object with an attack, the hit is a critical hit.

Adamantine Plating. The golem is immune to critical hits and to any effect a critical hit should trigger on it. Critical hits against the golem are treated as normal hits.

Multiattack. The golem makes two melee attacks.

Slam. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 25 (3d10 + 8) bludgeoning damage.

Morningstar. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 31 (3d12 + 10) bludgeoning or piercing damage.

Static Discharge (Recharge 6). The golem releases electrical energy in a 15-foot cone. Each creature in that area must make a DC 19 Dexterity saving throw, taking 54 (12d8) lightning damage on a failed save, or half as much damage on a successful one.