The Fairy Hound
The Cú Sídhe is the hound of the síde — the working dog of the Tuatha Dé Danann‘s Otherworld. After the Tuatha Dé lost Ireland to the Milesians and retreated into the fairy mounds, they brought their animals with them. The Cú Sídhe is one of those animals. It herds the supernatural cattle of the Otherworld and guards the mounds, the same way that dogs in the mortal world herded cattle and guarded farms. Except that it is the size of a calf, dark green, and completely silent.
The silence is its most unnerving quality. It moves without sound — no padding of paws, no movement through grass. It is simply there, where there was nothing a moment before. Its green colour is unmistakable — no natural dog is that colour. Something that size, that colour, moving that silently, is from the Otherworld, and anyone who knew what it was gave it a wide berth.
When it barks, the sound carries across enormous distances. It barks three times before a death — the first bark heard far off, the second closer, the third close enough to confirm what is coming. Those three barks were one of the most feared sounds in Irish and Scottish country life.
Interfering with the Cú Sídhe while it was working — getting between it and its cattle, trying to handle it, doing anything that disrupted the business of the Otherworld — was one of the more reliably catastrophic things a person could do.
Key facts about Cú Sídhe
- Name: Cú Sídhe (“hound of the fairy mound”); Cù Sìth in Scottish Gaelic
- Origin: The síde — the Otherworld of the Tuatha Dé Danann
- Type: Supernatural fairy hound; working dog of the Otherworld
- Size: Large as a calf or young bull
- Colour: Dark green (Irish); white with green ears (Scottish variant)
- Movement: Completely silent
- Death-warning: Three barks at increasing proximity before a death
- Function: Herds Otherworld cattle; guards fairy mounds; death-harbinger
- Division: Later folklore — though rooted in the ancient Tuatha Dé Danann world
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