Proto-Indo-European mythology also in the myths of the slaying of the nine-headed Lernaean Hydra by Heracles and the slaying of Python by Apollo. The story of Heracles's theft of the cattle of Geryon is probably also related. Although Heracles is not usually thought of as a storm deity in the conventional sense, he bears many attributes held by other Indo-European storm deities, including physical strength and a knack for violence and gluttony. The original Proto-Indo-European myth is also reflected in Germanic mythology. In Norse mythology, Thor, the god of thunder, slays the giant serpent Jörmungandr, which lived in the waters surrounding the
Orthrus overcome by Heracles in one of his labours. Orthrus In Greek mythology, Orthrus (, "Orthros") or Orthus (, "Orthos") was, according to the mythographer Apollodorus, a two-headed dog who guarded Geryon's cattle and was killed by Heracles. He was the offspring of the monsters Echidna and Typhon, and the brother of Cerberus, who was also a multi-headed guard dog. His name is given as either "Orthrus" ("Ὄρθρος") or "Orthus" ("Ὄρθος"). For example, Hesiod, the oldest source, calls the hound "Orthus", while Apollodorus calls him "Orthrus". According to Hesiod, Orthrus was the father of the Sphinx and the Nemean Lion, though