Athena (the daughter of Zeus and Metis). Apollodorus similarly states that Hera gives birth to Hephaestus alone, though he also relates that, according to Homer, Hephaestus is one of the children of Zeus and Hera.

Some sources state that the origin myth of Hephaestus was that of a "daemon of fire coming up from the Earth"--that he was also associated with gas "which takes fire