to which she answers calf's hide, of course, and tells him he should have asked about how to brew water (into beer), which would have benefited him more greatly. Merfolk as abductors The Swedish ballad "Hafsfrun" (≈, SMB 23, TSB A 51) is an instance where a mermaid kidnaps a human girl at age fifteen, and when the girl's brother accomplishes the rescue, the mermaid declares she would have cracked her neck if she knew she would be thus betrayed. The Swedish merman Hafsman[nen] steals a human woman to become his bride according to folklore. Marmaele As aforementioned, the mermaid () takes the merman () for husband, and produce children called marmæler (sing. , "sea-talkers"). which the fishermen sometimes bring home to gain insight into the future. Early sources say that Norwegian fishermen who capture the marmæte or marmæle may bring them home but do not dare keep it for more than 24 hours before turning them back into the sea whence they found it. 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. Western European folklore Melusine is a mermaid-like character from European folklore, cursed to take the form of a serpent from the waist down. Later depictions sometimes changed this to a fish tail, and in heraldry her name was sometimes used for a mermaid with two tails. The alchemist Paracelsus's treatise A Book on Nymphs, Sylphs, Pygmies, and Salamanders, and on the Other Spirits (1566) spawned the idea that the water elemental (or water sprite) could acquire an immortal soul through marriage with a human; this led to the writing of De la Motte Fouqué's novella Undine, and eventually