John Carter/Carson of Mars/Venus by Frank Frazetta

Just saw the first image as part of More Magic, but I know I've seen it a bazillion times before, just cannae remember where.  Maybe it's a Carson of Venus like the second image, or maybe it's John Carter of Mars, like when he wears a similar helmet as a Chessman of Mars.  Helmet and cape remind me of the third image, which had noth'n to do with either