The water-horse does not appear in bestiaries or the Physiologus, though it is found in some encyclopedias and other manuscripts. It is described as having the fore parts of a horse and the tail of a fish or snake. It is probably based on the sea-horse. The water-horse is written of in Greek and Roman mythology, and is depicted in carvings. Manuscript illustrations are very uncommon, though recognizable seahorses often appear along with other sea animals in images marking the start the fish sections in some texts.