Terrifying Iron Cobra

A nice counter to large parties of PCs with lots of actions. Used as part of the Bronze Liche encounter. I didn’t end up using the noxious fumes or poison breath weapon as only 1 PC was every engaged with the cobra. I also forgot 🙂 I used its dazing ability liberally though.

A nod to Rob Kuntz and his terrifying iron golem.

Terrifying Iron Cobra

Large construct, unaligned
Armor Class 20 (natural armor)
Hit Points 210 (20d10 + 10)
Speed 30 ft.
24 (7) 9 (-1) 20 (5) 3 (-4) 11 (0) 1 (-5)
Senses darkvision 120 ft., passive Perception 10
Languages understands the languages of its creator but can’t speak
Challenge 16

Lightning Absorption. Whenever the golem is subjected to lightning damage, it takes no damage and instead regains a number of hit points equal to the lightning 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.

Toxic Death. When the golem is first bloodied and when it is reduced to 0 hit points, poison breath recharges and the golem uses it. Change the range to a 15-foot sphere centred on the golem.

Noxious Fumes (Bloodied). All creatures that start or enter the area of the aura (within 10 feet of the golem) when it is reduced to half its starting hit points automatically takes 10 poison damage.


Cleave. The golem makes two dazing bite attacks.

Dazing Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 20 (3d8 + 7) piercing damage and the target is dazed (while dazed you grant advantage, and can only take 1 action per turn) and marked (a marked target has disadvantage on attacks against targets other than the golem).

The snake injects cockatrice poison into the target. The target must succeed on a DC 19 Constitution saving throw against being magically petrified. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified for permanently.  Even if the target succeeds on the saving throw unless it is immune to poison, it suffers one of the following random effects:

  1. Poison Damage: The target takes 13 (3d8) poison damage.
  2. Confusion: On its next turn, the target must use its action to make one weapon attack against a random creature it can see within 30 feet of it, using whatever weapon it has in hand and moving beforehand if necessary to get in range. If it?s holding no weapon, it makes an unarmed strike. If no creature is visible within 30 feet, it takes the Dash action, moving toward the nearest creature.
  3. Paralysis: The target is paralyzed until the end of its next turn.

Poison Breath (Recharge 6). The golem exhales poisonous gas in a 15-foot cone. Each creature in that area must make a DC 19 Constitution saving throw, taking 45 (15d8) poison damage on a failed save, or half as much damage on a successful one. In either case, the target takes 15 ongoing poison damage.


Dazing Bite. If a marked character moves while within 10 feet of the golem, the golem can make a dazing bit attack.

Legendary Actions

Action Point (1/Day). The golem can take an available action.