(Weird Comics 001, 1940)
Here's the thing about the Stone Man: I have no idea what his deal is, aside from the fact that he's a creep. See, the Bird Man is just flying around the desert one day, as is his wont, when he runs into some guys searching for one of the guys' daughter. After flying around for a bit, he discovers her in an isolated canyon, being sexually menaced by a weirdo and his animal companions. Why is he called the Stone Man? Not a clue. He's much more of an animal guy than a stone guy, in that he doesn't appear to have any stone-like qualities.
After the Bird Man defeats the Stone Man's coyotes, a vulture flies off with the girl and the Bird Man sets off in pursuit. He gets her away from it and returns her to her father and then... that's it. We see no more of the Stone Man. It's very anticlimactic!