Huge fey (merfolk, Shapechanger), neutral

Armor Class 15 (natural armor)
Hit points 136 (12d12 + 52)
Speed 40 ft., swim 60 ft.

20 (+5) 14 (+2) 18 (+4) 10 (+0) 12 (+1) 16 (+3)

Skills History +3, Perception +4, Persuasion +6, Stealth +5
Senses darkvision 120 ft., passive Perception 14
Languages Common, Sylvan
Proficiency Bonus +3
Challenge 6 (2,300 XP)


    • Amphibious. The mhorag can breathe air and water.
    • Innate Spellcasting. The mhorag’s innate spellcasting ability is Wisdom (spell save DC 11). It can innately cast the following spells, requiring no material components:
      • At will: control water
      • Keen Smell. The mhorag has advantage on Wisdom (Perception) checks that rely on smell.
      • Magic Resistance. The mhorag has advantage on saving throws against spells and other magical effects.


      • Multiattack. The mhorag makes two attacks: one with its Bite and one with its Tail Slap in serpent form and two with its Tail Slap in merfolk form.
      • Bite (Serpent Form Only). Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) piercing damage.
      • Tail Slap. Melee Weapon Attack: +8 to hit, reach 15 ft., one target. Hit: 16 (2d10 + 5) bludgeoning damage. Swallow (Serpent Form Only). The mhorag makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside The mhorag, and it takes 21 (6d6) acid damage at the start of each of The mhorag’s turns. If The mhorag takes 30 damage or more on a single turn from a creature inside it, The mhorag must succeed on a DC 15 Constitution saving throw at the end of that turn or regurgitate the swallowed creature, which falls prone in a space within 10 feet of The mhorag. If The mhorag dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 20 feet of movement, exiting prone. Wailing Howl (1/Day, Merfolk Form Only). Once per day, the mhorag can emit a mournful wail. Each creature within 30 feet of the mhorag must make a DC 14 Wisdom saving throw or become overcome with despair manifesting as unshakable dread. Until the despair ends, the creature has disadvantage on all saving throws and gains the following flaw: “I’m convinced that I’m going to die.” The creature can attempt to end its despair each time it finishes a long rest, doing so with a successful DC 14 Wisdom saving throw. A calm emotions spell also ends the despair, as does any spell or other magical effect that removes a curse.


      • Change Shape. The mhorag can polymorph into a Medium merfolk, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.


The mhorag is a massive aquatic creature resembling a hybrid of serpent and amphibian. It has a long, serpentine body covered in rough, green scales, and three prominent humps along its back. Its head is wide and featureless, with large red eyes that seem to glow in the darkness of the loch. The mhorag’s powerful tail ends in a broad fin that propels it through the water.

Mhorag’s inhabit the depths of the deepest lochs. They are known to move through the water silently, often resembling a dark heap or shadow in the depths. They occasionally surface during the full moon, when its red eyes can be seen illuminating the water’s surface.

Sightings of the creature date back centuries, with various accounts describing it as a large serpent-like being with humps on its back. A mhorag’s appearances are often associated with premonitions of death in local clans.

A mhorag’s natural form is a half-human, half-fish merfolk. The lower portions of her body are in the form of a salmon and the upper in the form of a small woman of with long flowing yellow hair falling down her snow-white back.

Mhorags are elusive creatures, rarely seen by humans. It tends to avoid confrontation and is known to be particularly active during the night. Its large size and powerful attacks make it a formidable predator in the loch, capable of hunting and swallowing creatures that venture too close to its territory. It prefers to ambush its prey, using its innate spellcasting ability to manipulate the water around it.

Section 15: Copyright Notice

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

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