Medium fey (shapechanger), neutral evil

Armor Class 13 (natural armor)
Hit Points 78 (12d8 + 24)
Speed 40 ft. (humanoid form), 60 ft. (hybrid or horse form), swim 40 ft.

16 (+3) 14 (+2) 15 (+2) 8 (-1) 10 (+0) 16 (+3)

Skills Animal Handling +3, Deception +6, Intimidation +6, Nature +2, Perception +3, Persuasion +6, Sleight of Hand +5, Stealth +5, Survival +3
Saving Throws Str +6, Cha +6
Damage Vulnerabilities fire
Damage Resistances poison
Condition Immunities charmed, frightened, poisoned
Senses darkvision 60 ft., Passive Perception 13
Languages Common, Sylvan
Proficiency Bonus +3
Challenge 6 (2,300 XP)


  • Amphibious. The glashtyn can breathe air and water.
  • Fey Ancestry. The glashtyn has advantage on saving throws against being charmed and can’t be put to sleep magically.
  • Keen Senses. The glashtyn has advantage on Wisdom (Perception) checks that rely on hearing or smell.
  • Magic Resistance. The glashtyn has advantage on saving throws against spells and other magical effects.
  • Sunlight Hypersensitivity. The glashtyn takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.


  • Multiattack. The glashtyn makes two attacks, only one of which can be a Bite attack.
  • Grabby Hands (Humanoid or Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: The target is grappled (escape DC 14) and takes 11 (2d10) psychic damage at the start of each of its turns until this grapple ends. The glashtyn can grapple only one creature at a time.
  • Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage.
  • Hooves (Horse or Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) bludgeoning damage.
  • Glamour (3/Day). The glashtyn magically projects an aura of deceptive charm. Creatures within 30 feet of the glashtyn must make a DC 14 Wisdom saving throw or be charmed for 1 minute. While charmed, the affected creature regards the glashtyn as a trusted friend and ally. The charmed creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the Glamour of any glashtyn for the next 24 hours.


  • Change Shape. The glashtyn can polymorph into a humanoid or into a horse, or back into its true form, which is horse-humanoid hybrid. Its statistics, other than its AC, 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. If the glashtyn hides its horse ears in its hybrid form, it requires a creature to take an action to visually inspect it and succeed on a DC 20 Intelligence (Investigation) check to discern that the glashtyn is disguised. Trampling Charge (Horse Form Only). If the glashtyn 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 glashtyn can make another attack with its hooves against it as a bonus action.


In its horse the glashtyn appears as an ordinary horse, but its true identity is revealed by its unusually long tail, often three yards in length.

Glashtyns tend to inhabit deep pools in isolated rivers or behind waterfalls, where they shift between their human-like and horse forms to deceive and lure unsuspecting victims. They are predatory creatures, known for their alluring charm and dangerous intent towards young women. In their human-like forms, they will attempt to entice their victims with strings of pearls, only to reveal their true nature with their pointed ears and sharp, pointed teeth.

The glashtyn is particularly dangerous when encountered near bodies of water, and it is believed to have the power to drag women to their doom. To protect their communities from these dangerous creatures, some have devised clever methods to drive them away. One story tells of a man disguising himself as a woman and sitting spinning in his home, luring the glashtyns with curiosity. When a group of young glashtyns gathered, interested in this new girl in the neighborhood, he surprised them by pelting them with burning peat, a shock that was sufficient to drive them off permanently.

However, not all glashtyns are malevolent. There are accounts of glashtyns that take the form of helpful farmhands, assisting with tasks like threshing corn and playing among the flocks in the shape of a lamb. These glashtyns are generally good-natured, but they can be dim and easily offended.

Section 15: Copyright Notice

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

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