Justice League of America #20

In "The Mystery of Spaceman X!", the Justice League of America faces a bizarre threat when an alien manipulates a colossal spaceman suit to siphon disaster-energy, growing stronger with every catastrophe. Written by Gardner Fox and illustrated by Mike Sekowsky, with inks by Bernard Sachs and lettering by Gaspar Saladino, this 1963 classic sees Superman step in to break the alien’s hold—though the true nature of the spaceman remains a mystery. The cover, by Mike Sekowsky and Murphy Anderson, captures the eerie scale of the giant figure looming over a city in peril.