Phthonus was the personification of envy in Greek mythology, the other half of the goddess of retribution, Nemesis. He was the son of Nyx (night) and Dionysus, although other sources cite him as the son of Aphrodite, goddess of love. Phthonus had a number of wives, whom he killed because he suspected they were unfaithful to him. Apart from mortals, he also influenced the gods, such as Hera, whom he informed about the adulterous affairs of her husband, Zeus. It was his plan that killed Semele, one of Zeus' lovers, when she asked him to appear in his full glory, thus burning her instantly.
See Also: Nemesis, Nyx, Dionysus, Aphrodite, Hera, Zeus, Semele