And the canon dnd Gorgon creature is what? A metal bull?? That's just silly.

Yeah. Its existence comes from the 1658 "THE HISTORY OF Four-Footed Beasts," and I see why game designer Gygax thought using Medusa for one type of monster and Gorgon for another made for a richer more interesting monster set... But of course, then the Monster Manual became the best known source.