Caduceus is a continuation of the older Indo-European dragon-slayer motif. Wilhelm Heinrich Roscher (1913) pointed out that the serpent as an attribute of both Hermes and Asclepius is a variant of the "pre-historic semi-chthonic serpent hero known at Delphi as Python", who in classical mythology is slain by Apollo. One Greek myth of origin of the caduceus is part of the story of Tiresias, who found two snakes copulating and killed the female with his staff. Tiresias was immediately turned into a woman, and so remained until he was able to repeat the act with the male snake seven years later.
Horned Serpent of a Lindorm in Northern Europe, especially in Southern Scandinavia, and most of all as described in folklore in Eastern Denmark (including the provinces lost to Sweden in 1658). There, too, it is a water creature of huge dimensions, while in Southern Sweden it is a huge snake, the sight of which was deadly. This latter characteristic is reminiscent of the basilisk. In Mesopotamian mythology Ningishzida, is sometimes depicted as a serpent with horns. In other depictions, he is shown as human but is accompanied by "bashmu", horned serpents. Ningishzida shares the epithet "ushumgal", "great serpent", with several other Mesopotamian