In Scottish Highlands folklore, the Cù-sìth is a spectral hound of enormous size, said to be as large as a calf, with shaggy green fur and glowing eyes. It prowls the moors and rocky coasts of the Hebrides, where locals dread its appearance. The beast’s eerie howl was believed to come in threes — if heard, death would soon follow. Highlanders said the Cù-sìth would stalk souls to the underworld, much like the hounds of Celtic myth in Ireland and Wales. Its legend lingers in Gaelic oral tradition, and is sometimes tied to modern phantom dog sightings on Scotland’s isles.