What is "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.

According to Hesiod, Orthrus was the father of the Sphinx and the Nemean Lion, though who Hesiod meant as the mother, whether Echidna, the Chimera, or Ceto, is unclear.

Orthrus is a spider genus of the Salticidae family (jumping spiders).