quality:correction
Margýgr

Jón Árnason describes the margýgur as yellow-haired woman who is fish from the waist down, who drags careless seamen to the depths of the sea.

However, margygr literally means something like "mer-troll", and in medieval tradition, the margygr is more of a "sea monster" or "sea-ogress".

According to a version of the Saga of St. Olaf (Olaf II of Norway) the king encountered a margygr whose singing lulled voyagers to sleep causing them to drown and whose high-pitched shrieks drove men insane. Her physical appearance is described thus: "She has a head like a horse, with ears erect and distended nostrils, big green eyes and fearful jaws. She has shoulders like a horse and hands in front; but behind she resembles a serpent". This margygr was also said to be furry like a seal, and gray-colored.