Cat-sìth is the ‘faerie cat’, it resembles a large black cat with a distinctive white spot on its chest and often walks on its hind legs. There’s also the ‘faerie dog’, cù-sìth has a shaggy, dark green coat and being the size of a Highland cow; a silent hunter it will occasionally let out three terrifying barks, but only three, as an ill omen. There’s also a ‘faerie mouse’, the common shrew, lucha shith.
In the Highlands, Fairies keep the company of red deer and cattle. These ‘faerie cattle’ are crodh sìth and crodh mara and live in both the sea and in lochs. Red deer and goats are the ‘cattle of the fairies’, being milked by them. In the lullaby, Bainnen am fiadh translated by a Dr. Carmichael: “On milk of deer was I reared, On milk of deer was nurtured, On milk of deer beneath the ridge of storms, On crest of hill and mountain.”
I remember walking in Torridon some 30 years ago. It was a crisp winter’s day, and snow was piled high at the side of the road. No other humans were in sight. There was much birdsong, and the occasional piercing dog bark. It reminded me of the tale of the fairie dog and I wrote this Haiku:
walking in Torridon / my only companion / single barking dog
Folklore of Scotland 