B.I.G. Welder Omega

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 Weapons. The golem's weapon attacks are magical.

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

Multiattack. The golem makes two welder attacks.

Welder. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 16 (6d6 + 5) fire damage.

Boil Wave (Recharge 5-6). The welder vents a line of boiling water or steam in a 30-foot line that is 5 feet wide. Each creature in that line must make a DC 17 Dexterity saving throw, taking  49 (16d6) fire damage on a failed save, or half as much on a successful one.

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 21 (4d10) 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.