John Carter, Warlord of Mars #13

March of the Dead!" sets an appropriately grim stage on this 1978 Marvel issue, where a fearsome, dark-skinned warrior — identifiable as Tars Tarkas — looms over the cover with sword raised, locked in brutal combat amid a chilling landscape of countless skulls. A struggling figure is caught in his grip while, in the background, John Carter himself appears poised to intervene. Cover art by George Pérez and inker Rudy Nebres gives the whole scene a raw, kinetic energy that perfectly matches the cover's own warning: "There can be no escape! John Carter must die!