John Carter, Warlord of Mars #12

Based on Edgar Rice Burroughs' beloved pulp hero, this 1978 Marvel issue drops John Carter into a harrowing gauntlet as the cover — penciled by George Pérez and inked by Rudy Nebres — depicts the muscular Warlord of Mars slashing his way through a surging horde of skeletons in a darkened, bone-strewn chamber. The tagline "City of the Dead" sets an ominous tone that perfectly matches the interior story title "City of Skulls," promising a descent into one of Barsoom's most macabre corners. Pérez and Nebres deliver a visceral, kinetic image that captures everything compelling about Carter's world — swashbuckling action, alien peril, and a hero who never backs down.