The mythological hero famed for his armor made from the skin of the Nemean Lion is Heracles, or Hercules in Roman mythology. This legendary hero undertook the Twelve Labors, with the slaying of the Nemean Lion being the first. After defeating the lion, he wore its impenetrable skin as armor, symbolizing his strength and valor. This act not only represents his physical prowess but also signifies his status as a quintessential hero in both Greek and Roman traditions.