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

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

Metal Joints. Upon being submerged in 10 feet of water, the golem has disadvantage on it's kick attack and it's speed is halved for 1d4 rounds, upon being submerged in 30 feet of water, the golem has disadvantage on it's chainsaw attack for 1d4 rounds.

Rumbling Parts. The golem's insides are always making a rumbling sound, for as long as it is alive, it has advantage on Charisma (Intimidation) checks and disadvantage on Dexterity (Stealth) checks.

Multiattack. The golem makes two chainsaw attacks.

Chainsaw. Melee Weapon Attack: +14 to hit, reach 10 ft., 1 target. Hit: 25 (3d12 + 6) slashing damage. 

Violent Outburst (Recharge 5-6). The golem makes a piercing screech of voice and scraping metal that can be heard from a mile away. Each creature within 120 feet of the golem must make a DC 19 Constitution Saving Throw, with advantage if they are more than 60 feet away. On a failed save a creature takes 55 (10d10) thunder damage, or half as much on a successful one. Creatures that fail the save must repeat it, becoming deafened on a fail, they can repeat this save at the end of their turns, ending the effect on success. The golem then make one chainsaw attack.

The golem can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The golem regains spent legendary actions at the start of its turn.

Chainsaw. The golem makes a chainsaw attack.

Sweep (Costs 2 Actions). The golem makes a low roundhouse kick, sweeping it's enemies from below in a 20 foot cone. Each creature within the area must make a DC 18 Dexterity Saving Throw, taking 14 (4d6) bludgeoning damage and being knocked prone on a failed save, or half as much and not being knocked prone on a successful one.