C.J.S. Thompson, a former curator at the Royal College of Surgeons of England, noted in his book "The Mystery and Lore of Monsters" (Kessinger, 2010), "Traditions concerning creatures half-human and half-fish in form have existed for thousands of years, and the Babylonian deity Era or Oannes, the Fish-god, is represented on seals and in sculpture, as being in this shape over 2,000 years B.C. He is usually depicted as having a bearded head with a crown and a body like a man, but from the waist downwards, he has the shape of a fish covered with scales and a tail.