Hag, Muileartach

Family: Hags

Medium fey (hag, Shapechanger), chaotic evil

Armor Class 14 (natural armor)
Hit Points 97 (13d8 + 39)
Speed 30 ft., swim 40 ft.

18 (+4) 14 (+2) 16 (+3) 12 (+1) 14 (+2) 13 (+1)

Skills Deception +4, Nature +4, Perception +5, Persuasion +4, Intimidation +4, Stealth +5, Survival +5
Damage Vulnerabilities cold
Damage Resistances acid; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., Passive Perception 15
Languages Common, Sylvan
Proficiency Bonus +3
Challenge 8 (3,900 XP)


  • Amphibious. The muileartach can breathe air and water.
  • Keen Smell. The muileartach has advantage on Wisdom (Perception) checks that rely on smell.
  • Fey Ancestry. The fey has advantage on saving throws against being charmed and can’t be put to sleep magically.
  • Freeze. If the muileartach takes cold damage, it partially freezes; its speed is reduced by 20 feet until the end of its next turn.
  • Magic Resistance. The muileartach has advantage on saving throws against spells and other magical effects.
  • Misty Escape. When it drops to 0 hit points outside the ocean, the muileartach transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious. If it can’t transform, it is destroyed. While it has 0 hit points in mist form, it can’t revert to its muileartach form, and it must reach the ocean within 2 hours or be destroyed. Once fully submerged in the ocean, it reverts to its muileartach form. It is then paralyzed until it regains at least 1 hit point. After spending 1 hour in its resting place with 0 hit points, it regains 1 hit point.
  • Spell-Like Abilities. The muileartach can cast the following spells using its cauldron as a material component:


  • Multiattack. The muileartach makes three attacks: one with its Bite and two with its Claws.
  • Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage or 18 (4d6 + 4) piercing damage when enlarged.
  • Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d4 + 4) slashing damage or 14 (4d4 + 4) slashing damage when enlarged. Whelm (Recharge 4 6). Each creature in the muileartach’s space must make a DC 15 Strength saving throw. On a failure, a target takes 13 (2d8 + 4) bludgeoning damage. If it is Large or smaller, it is also grappled (escape DC 15). Until this grapple ends, the target is restrained and unable to breathe unless it can breathe water. If the saving throw is successful, the target is pushed out of the muileartach’s space. The muileartach can grapple one Large creature or up to two Medium or smaller creatures at one time. At the start of each of the muileartach’s turns, each target grappled by it takes 13 (2d8 + 4) bludgeoning damage. A creature within 5 feet of the muileartach can pull a creature or object out of it by taking an action to make a DC 15 Strength check and succeeding.
  • Enlarge (Recharges after a Short or Long Rest). For 1 minute, the muileartach magically increases in size, along with anything it is wearing or carrying. While enlarged, the muileartach is Large, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and makes Strength checks and Strength saving throws with advantage. If the muileartach lacks the room to become Large, it attains the maximum size possible in the space available.


  • Change Shape. The muileartach polymorphs into a Medium humanoid in the form of an old woman or a Medium cloud of mist, or back into its true form. While in mist form, the muileartach can’t take any actions, speak, or manipulate objects. It is weightless, has a flying speed of 20 feet, can hover, and can enter a hostile creature’s space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and it can’t pass through water. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to all nonmagical damage.


The muileartach is a monstrous hag with blue-black face dominated by a single, swift-moving eye. Long, streaming hair resembling seaweed trails from its head. Its clawed limbs end in rust-colored, bone-tufted extremities, and its body is covered in patches of dark and grey hide.

The muileartach is a legendary creature said to rise from the depths of the ocean, particularly during stormy nights and winter. It is often associated with treacherous waters, icy storms, and rocky shores. Its presence is an omen of great danger, foretelling impending tempests and tumultuous seas.

The muileartach emerges from the watery underworld to cause havoc and destruction, often associated with storms that rage across the seas. The muileartach is drawn to coastal cottages during storms, where it disguises itself as a dripping old woman begging for shelter and warmth. Those who unknowingly let her inside experience a horrifying transformation, as the muileartach swells into an enormous form, wreaking havoc within.

Despite its destructive nature, the muileartach possesses a unique ability to heal. It carries a pot of balsam that can mend wounds and alleviate sickness. Legends tell of its power to even restore the dead to life by gently poking its wizened finger into their mouths.

Section 15: Copyright Notice

5E RPG: Celtic Bestiary. Copyright 2023, Mal and Tal Enterprises, LLC; Author Michael Tresca.

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