Nam-Ek
From superman.nu: Supermanica
A Kryptonian who makes himself immortal using the fabled horns of the Rondors. The effects of his actions cause him to mutate into a disfigured horned-monster, a man who cannot die but who must also forever live alone because of his appearance. Nam-Ek survives for 500 years and is isolated in space when Krypton explodes. Later exiled to the Phantom Zone he tries to exact revenge against Superman when he is released (first appearance in S No. 282, Dec 1974: "Loneliest Man in the Universe!"). Also, see Amalak.
