Aderyn y Corph

Tiny undead (familiar), neutral

Armor Class 13 (natural armor)
Hit Points 4 (1d4 + 2)
Speed 10 ft., fly 50 ft. (hover)

2 (-4) 14 (+2) 15 (+2) 6 (-2) 12 (+1) 5 (-3)

Skills Perception +3, Stealth +4
Damage Immunities poison
Condition Immunities exhaustion, poisoned
Senses darkvision 60 ft., passive Perception 13
Languages Common
Proficiency Bonus +2
Challenge 1/4 (50 XP)


  • Familiar. The aderyn y corph can serve another creature as a familiar, forming a telepathic bond with its willing master, provided that the master is at least a 3rd-level spellcaster. While the two are bonded, the master can sense what the aderyn y corph senses as long as they are within 1 mile of each other. If its master causes it physical harm, the aderyn y corph will end its service as a familiar, breaking the telepathic bond.
  • Mimicry. The adern y corph can mimic simple sounds it has heard, such as a person whispering, a baby crying, or an animal chittering. A creature that hears the sounds can tell they are imitations with a successful DC 10 Wisdom (Insight) check.
  • Undead Nature. The aderyn y corph doesn’t require air, food, drink, or sleep.


  • Beak. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 1 piercing damage.
  • Dewch. The aderyn y corph emits a shriek that sounds like “dewch” or “come” in Common until the start of its next turn or until it drops to 0 hit points. This shriek can be heard within a range of 300 feet.
  • Invisibility. The aderyn y corph magically turns invisible until it attacks or casts a spell, or until its concentration ends (as if concentrating on a spell). Any equipment the aderyn y corph wears or carries is invisible with it.


This bird has a skeletal appearance, lacking feathers and skin. Its eyes are hollow, giving it a haunting gaze.

The aderyn y corph (a-DEH-rin-uh-COR), also known as the corpse bird, is a small, ominous creature resembling a bird. The bird emits an eerie aura of death, which can be sensed by those nearby.

The aderyn y corph is believed to hide invisibly when not foretelling death. It is often associated with supernatural occurrences and is considered a harbinger of doom. The bird is commonly found near locations where imminent death is foretold, such as the homes of individuals nearing the end of their lives.

The aderyn y corph is a favorite of necromancers, who often use them as familiars due to their ability to remain unobtrusive until needed, and their value as sleepless guardians.

Section 15: Copyright Notice

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

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