The Mermaid Chronicles: The Merrow

The Merrow, or if you write it in Irish, Moruadh or Murrughach, from muir (sea) and oigh (a maid), is not uncommon they say on the wilder coasts. The fishermen do not like to see them for it always means coming gales.

The male Merrows (yes, they do exist depending upon which legends you read) usually have green teeth, green hair, pig's eyes, red noses, and duck-like scales between their fingers.

Sometimes they prefer good-looking fishermen to their sea lovers. Near Bantry in the last century, there is said to have been a woman covered all over with scales like a fish who was descended from such a marriage. Sometimes they come out of the sea and wander about the shore in the shape of little hornless cows. 

Whatever we choose to call them, the merrows are usually described as incredibly beautiful maidens with long green hair, and flat feet with webbed fingers and toes for better swimming. The merrows sing seductively, just like Greek sirens. However, unlike the sirens, the merrow don’t do this to tempt sailors to their doom. They’re not as malevolent as the sirens. Instead, they usually take sailors and fishermen to live with them underwater, entranced to love, follow, and obey the merrow’s every wish. 

(Reference: Mermaid.Net and https://symbolsage.com/the-merrow-mythology)