Well, hey, Hephaestus was a Greek god, right? God of the forge? They didn't specify! LOL! This is in no way a comment on Jim's looks-- I've never set eyes on him.
Below, from Wikipedia:
Hephaestus was reported in myth as cholo-s, “lame”, crippled,
halting (e-pedanos) and misshapen, either from birth or as a
result of his fall: in the vase-paintings, Hephaestus was shown
lame and bent over his anvil, his feet sometimes back-to-front:
Hephaistos amphigye-eis. He walked with the aid of a stick. The
Argonaut Palaimonius, “son of Hephaestus” which is to say a
bronze-smith was also lame. Other “sons of Hephaestus” were the
Kabeiroi on the island of Samothrace; they were identified with
the crab (karkinos) by the lexicographer Hesychius, and the
adjective karkinopous, “crab-footed” signified “lame”, Detienne
and Vernant have observed: the Kabeiroi were seen as lame too.
Hephaestus’s physical appearance indicates arsenicosis, low
levels of arsenic poisoning, resulting in lameness and skin
cancers. In place of less available tin, arsenic was added to
copper in the Bronze Age to harden it; most smiths of the Bronze
Age would have suffered from chronic workplace poisoning, and the
mythic image of the lame smith is widespread.