Stab him, poison him, wave a magic wand at him, throw him into the sun Superman will always come back. Or, if you're the Time-Trapper, you could essentially just wait it out until it's the end of his life and then he'll just die of natural causes. That's the long and the short of Even A Superman Dies! from 1970's Action Comics #387. Superman, already knocking on a bit in this future-set story, goes to break some astronauts out of time bubbles that send them reeling through history. He accidentally enters a defective one booby-trapped by the Time-Trapper, which makes him age to about a million. Unfortunately, being old as balls isn't Superman's only issue. There's also the fact that he's alone in the universe save for a huge cosmic spike Lex Luthor made before he died, powered by evil psyche-energy, which hunts the elderly Man Of Steel down and puts him in his place, because if he fought too hard against it he'd break his hip probably.