Steam Golem

If the steam golem starts its turn immersed in water, or if it was soaked with at least 20 gallons of water on its previous turn, it risks losing steam pressure in its boiler. The steam golem must succeed on a DC 20 Constitution saving throw or its internal fire is extinguished. Until its internal fire is relit, the golem’s speed is halved, its AC is reduced by 2, and it must repeat the saving throw at the start of each of its turns. On a failure, it stops repeating this saving throw and becomes dormant, effectively dead until the fire is relit. A Medium or smaller creature within 5 feet of the golem can take an action to relight the golem’s internal fire, making it active again.

The golem doesn’t require air, food, drink, or sleep.

The steam golem’s weapon attacks are magical. When the golem hits with any weapon, the weapon deals an extra 4d8 fire damage (included in the attack).

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

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

Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 22 (4d6 + 8) slashing damage plus 18 (4d8) fire damage.

Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 26 (4d8 + 8) slashing damage plus 18 (4d8) fire damage.

The steam golem makes one Axe Arm attack and one Long Axe attack.

The steam golem releases a blast of steam in a 30-foot cone or in a 10-foot-radius cloud that extends from it, spreading around corners. Each creature in the area must make a DC 17 Dexterity saving throw, taking 54 (12d8) fire damage on a failed save, or half as much damage on a successful one.

When a creature the steam golem can see within 30 feet of it casts a spell, the steam golem emits a shriek from its twin steam whistles. The spellcaster must succeed on a DC 17 Constitution saving throw or the spell fails and has no effect.