Merrows
Good or bad weather, the male merrow sits on a rock, scanning the sea for cases of brandy lost from wrecked ships. He is a friendly fellow with a red nose (some say from a wee bit too much drinking of that brandy). He is a bringer of good luck. He wears a red cocked hat and has a green body, with green hair and teeth. He has the eyes of a pig, scaly legs, arms like fins and wears no clothes. It's no small wonder that the beautiful female merrows seek husbands in mortal lands.
The female merrow (mulrruhgach), also called a mermaid (murúch) or a sea-maiden (maighdean mhara), is lovely and graceful. She has the tail of a fish and web-like scales between her fingers. She sometimes wears a gown as white as the sea foam. The gown is trimmed with red and purple seaweeds. The sea water on her hair glistens like dew when the rays of the sun's morning light shines upon it. She also wears a red hat which suits her alluring face with its mocking eyes. Sometimes she wears a dark sleeveless cloak that clings about her, half-revealing the voluptuous curves of her body.
She teases men with her beauty. In legends the singing of a mermaid, or her sirensong, is described as irresistible. As she lounges upon the rocks, she attempts to attract fishermen to her. But if he comes too near, she dives into the sea, laughing at the men. Little joy do they get from her, for her presence always ensures a storm or a disaster at sea. When a sailor fails to come home from the sea it is sometimes said he "married a mermaid". She upsets the waves and causes rain to fall from the sky. Ships at sea are cracked like straws. Small boats and rafts capsize. To her this is a delightful diversion.
On the sea she is as wild as she is alluring, but on land she becomes shy and submissive to men. Many Irish women emigrated to other lands causing many fishermen to linger by the sea long after work in hopes that a female merrow might appear.
If a man can capture her red cap or cloak, she will forget her past life and quietly marry him. She is an obedient and loving wife. Although she is always mindful of her husband and her household duties, she never quite adjusts to living on land. A married merrow laughs rarely. Her greatest emotions are ones of a quiet caring.
If she finds her cap or cloak (the husband seems to rarely hide the cap or cloak well and they never destroy them), and she sets the cap on her head or the cloak about her body, she will remember her past watery life and will joyfully abandon her home and her mate for the sea. When she remembers her past marine life she regains her youth and beauty that she lost while among the mortals.
Selkies
The selkies are gentler creatures who are seals by day but men and women by night. They are also called water kelpies, seal people or selchies. In their mortal form the selkies are described as posessing an unearthly beauty with dark hair and eyes. Silently they emerge from the sea to shed their skins and frolic on the sand. Like the merrows they have webs between their fingers and toes (or at least wide palms that hint of their watery origin) and must obey anyone who secures their oily skins. Selkies, also, make excellent wives. But they are solitary and quiet by nature. They will frequently wander from their mortal homes to the sea cliffs to meditate and sing their melancholy songs. When their fishermen-husbands are lost upon the sea, they sing from the cliffs to guide them home.
If they ever find their seal skins again, they, too, will return to the sea. But unlike the merrow, the selkie will not forget her husband and children and can be seen swimming close to the shore watching over them.