Medium undead
- Armor Class
- 16 (breastplate)
- Hit Points
- 135 (18d8 + 54)
- Speed
- 30 ft.
- Challenge
- 10 (5,900 XP)
- Saving Throws
- Con +7
- Skills
- Perception +6
- Damage Resistances
- cold; lightning; poison
- Condition Immunities
- charmed; frightened; poisoned
- Senses
- truesight 120 ft., passive Perception 16
- Languages
- understands the languages it knew in life but can't speak
Traits
If the dullahan is reduced to 0 hit points, it doesn't die or fall unconscious. Instead, it regains 97 hit points. In addition, it summons three death's heads, one of each type, in unoccupied spaces within 5 feet of it. The death's heads are under the dullahan's control and act immediately after the dullahan in the initiative order. Additionally, the dullahan can now use the options in the "Mythic Actions" section. Award a party an additional 5,900 XP (11,800 XP total) for defeating the dullahan after it uses Headless Summoning.
If the dullahan fails a saving throw, it can choose to succeed instead.
The dullahan doesn't require air, food, drink, or sleep.
Actions
The dullahan makes two attacks.
Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage, or 9 (1d10 + 4) slashing damage if used with two hands, plus 11 (2d10) necrotic damage. If the dullahan scores a critical hit against a creature, the target must succeed on a DC 15 Constitution saving throw or the dullahan cuts off the target's head. The target dies if it can't survive without the lost head. A creature that doesn't have or need a head, or has legendary actions, instead takes an extra 27 (6d8) slashing damage.
Ranged Spell Attack: +7 to hit, range 120 ft., one target. Hit: 14 (2d10 + 3) fire damage.
Legendary Actions
The dullahan makes one attack.
Each creature of the dullahan's choice within 30 feet of it must succeed on a DC 15 Wisdom saving throw or become frightened of the dullahan until the end of its next turn.
The dullahan moves up to its speed without provoking opportunity attacks and makes one Battleaxe attack with advantage. If the attack hits, but is not a critical hit, the attack deals an extra 27 (6d8) necrotic damage.
Mythic Actions
If the dullahan's Headless Summoning trait is active, it can use the options below as legendary actions.
The dullahan makes a Battleaxe attack, and then one death's head the dullahan can see within 30 feet of it can use its reaction to make a melee attack.
An echoing shriek issues from the dullahan's headless stump. Each creature of the dullahan's choice within 10 feet of it must make a DC 15 Wisdom saving throw. Each creature takes 16 (3d10) psychic damage on a failed save, or half as much damage on a successful one. If one or more creatures fail the saving throw, the dullahan gains 10 temporary hit points.