Medium fey (mount, shapechanger), neutral evil

Armor Class 17 (natural armor)
Hit Points 39 (6d6 + 18)
Speed 30 ft. (60 ft. in horse form), swim 40 ft.

18 (+4) 15 (+2) 16 (+3) 10 (+0) 12 (+1) 14 (+2)

Skills Perception +3, Performance +4, Stealth +4
Damage Vulnerabilities fire
Damage Immunities poison; bludgeoning, piercing, and slashing from nonmagical attacks that aren t iron
Condition Immunities poisoned, prone
Senses darkvision 60 ft., passive Perception 13
Languages Common, Sylvan
Proficiency Bonus +2
Challenge 4 (1,100 XP)


  • Amphibious. The kelpie can breathe air and water.
  • Beast of Burden. The kelpie is considered to be one size larger for the purpose of determining its carrying capacity.
  • Death Throes. When the kelpie dies, it bursts into a shapeless jelly-like clump. Each Medium or smaller creature within 5 feet of it must succeed on a DC 12 Dexterity saving throw or be restrained until the end of the creature’s next turn.
  • False Appearance. When not using any of its powers, the kelpie appears to be a normal horse. A creature can take an action to visually inspect the hose and succeed on a DC 16 Intelligence (Investigation) check to discern that it is a kelpie.
  • Fey Ancestry. The fey has advantage on saving throws against being charmed, and magic can’t put it to sleep.
  • Saddle. The kelpie can wear a saddle on its back. Two Medium or six Small creatures can sit on the saddle without squeezing. To make a melee attack against a target within 5 feet of the kelpie, they must use spears or weapons with reach. If the kelpie dies, creatures fall straight down, taking falling damage, and land in unoccupied spaces within 5 feet of the kelpie s position on the ground.
  • Sticky. The kelpie has advantage on Strength (Athletics) checks made to grapple and any ability check made to maintain a hold on another creature, a surface, or an object. The kelpie can also climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
  • Water Bound. The kelpie dies if it leaves the water to which it is bound or if that water is destroyed.


  • Multiattack. In humanoid form, the kelpie makes two melee attacks. In hybrid form, the kelpie makes three attacks: one with its Bite and two with its Claws.
  • Battleaxe (Humanoid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage, or 9 (1d10 + 4) slashing damage if used with two hands.
  • Bite (Hybrid or Horse Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 6 (1d4 + 4) piercing damage.
  • Claw (Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) slashing damage. If the target is Medium or smaller, it is grappled (escape DC 14) and pulled 5 feet toward the kelpie. Until this grapple ends, the target is restrained, the kelpie tries to drown it, and the kelpie can’t constrict another target.
  • Hooves (Horse Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
  • Luring Song. The kelpie sings a magical melody. Every humanoid and giant within 300 feet of the kelpie that can hear the song must succeed on a DC 11 Wisdom saving throw or be charmed until the song ends. The kelpie must take a bonus action on its subsequent turns to continue singing. It can stop singing at any time. The song ends if the kelpie is incapacitated. While charmed by the kelpie, a target is incapacitated and ignores the songs of other kelpies. If the charmed target is more than 5 feet away from the kelpie, the target must move on its turn toward the kelpie by the most direct route. It doesn’t avoid opportunity attacks, but before moving into damaging terrain, such as lava or a pit, and whenever it takes damage from a source other than the kelpie, a target can repeat the saving throw. A creature can also repeat the saving throw at the end of each of its turns. If a creature’s saving throw is successful, the effect ends on it. A target that successfully saves is immune to this kelpie’s song for the next 24 hours.


  • Change Shape. The kelpie can polymorph into a Medium humanoid, Small hawk, a Large horse, or back into its true form. Its statistics, other than its speed and size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. The kelpie reverts to its true form if it dies. Trampling Charge (Horse Form only). If the kelpie moves at least 20 feet straight toward a creature and then hits it with a hooves attack on the same turn, that target must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the kelpie can make another attack with its bite against it as a bonus action.


  • Sticky Hide. When a creature misses the kelpie with a melee weapon attack, it sticks to the kelpie’s hide. The attacker must succeed on a DC 14 Strength saving throw, or the weapon becomes stuck to the kelpie’s hide. If the weapon’s wielder can’t or won’t let go of the weapon, the wielder is grappled while the weapon is stuck. While stuck, the weapon can’t be used. A creature can pull the weapon free by taking an action to make a DC 14 Strength check.


The kelpie is a creature of breathtaking beauty, appearing as a majestic horse of the finest quality. Its form is sleek and muscular, with a glossy coat that shimmers in various shades of black and dark blue. The kelpie’s eyes are mesmerizing, drawing in those who gaze upon them. Its mane and tail cascade like flowing water, rippling with an ethereal glow.

Kelpies are found in bodies of water such as lochs, rivers, and streams. They are amphibious creatures, equally comfortable on land and in the water. Kelpies claim a stretch of coast up to 10 miles long as their territory.

Kelpies are carnivorous creatures that come on land to hunt and feed. They prey on cattle, sheep, and anything else they can catch. Kelpies are known to allow themselves to be mounted, but once a rider is on their back, they bolt straight for the water, carrying the rider under the waves to drown them. They possess the ability to make their back skin highly adhesive, making it difficult for riders to break free.

Kelpies are aggressive hunters, using their speed and strength to catch their prey. They attack with crushing hooves and sharp teeth, and they can deliver a double rear-hoof kick for extra damage. Their ability to swim and move swiftly in the water makes them formidable predators.

Kelpies are solitary creatures and rarely form social bonds. They live indefinitely until killed and have no known reproductive habits. They have no natural enemies but are sometimes hunted down by humans or merfolk when their depredations become intolerable.

Kelpies possess average to high intelligence and are capable of assuming human form at will. It can appear as a horse, a golden boy wearing a red cap, an old man with a dripping beard, or a handsome youth with a horse’s body and legs. In human form, they may try to lure unsuspecting travelers into the water to be devoured. Some kelpies can speak the local human language and may even be fluent in other languages.

Section 15: Copyright Notice

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

This is not the complete section 15 entry - see the full license for this page