B.I.G. Miner Sigma

Charge. If the golem moves at least 10 feet straight toward a target and then hits it with a drill attack on the same turn, the target takes an extra 25 (6d8) bludgeoning damage. If the target is a creature, it must succeed on a DC 18 Strength saving throw or be pushed up to 10 feet away and knocked prone.

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 Weapons. The golem's weapon attacks are magical.

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

Multiattack. The golem makes two power drill attacks.

Power Drill. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 22 (3d10 + 6) piercing damage.

Harpoon Gun. Ranged Weapon Attack: +4 to hit, 20/60 ft., one target. Hit: 17 (4d8) piercing damage. If the target is a Huge or smaller creature, it must succeed on a Strength contest against the golem or be pulled up to 20 feet toward the golem.

Mighty Bellow (Recharge 5-6). The golem lets out a loud bellow that disorients enemies. Each creature within 10 feet of the golem must succeed on a DC 16 Constitution saving throw, taking 26 (5d10) thunder damage and is Incapacitated until the end of it's next turn on a failed save, or half as much damage on a successful one.