Superman: Warrior of Mars!
By request: Superman #417, "Warrior of Mars", by Elliot S! Maggin and Curt Swan.
So, what would have happened if Baby Kal-El's rocket had landed on Mars, instead of Earth? Let's find out!
Our diaper-clad Kryptonian is found by a warlike tribe, led by Commander Norr:
Norr's tribe goes on to conquer most of Mars, until the only opposition left is a fat slob named "Dumumbluh the Incoherent". As Norr's and Dummy's armies have their final showdown, Norr reveals his secret weapon: His now-grown son, Skaggerak:
Having conquered all of Mars, Norr and Skaggerak grow bored, and turn their sights on the planet next door (that'd be us):
After getting a free meal at the soup kitchen, Skaggy gets recruited to dress up as Santa and collect money for charity. He doesn't really understand the concept, but plays along. He witnesses an attempted purse-snatching, which gets foiled by a couple of nice neighborhood kids:
(Not shown is a scene where the Daily Planet gang sit around and try to figure out what to call this Martian-who-wears-a-symbol-that-just-happens-to-look-exactly-like-an-S.)
And finally, we get the epilogue, explaining why the Mariner Probe found no sign of this advanced civilization living on Mars: