C. W. Saturn
"The pillar spun and swirled into the solid form, four meters long from horns to hooves, of the dark fallen angel of fable. C. W. Saturn took the form he had devised an age ago to strike terror into the hearts of humans. It was the leathery-winged, goat-like devil, spurs at its joints, beard reaching from its pointed chin, nostrils distending in hypnotic rhythm." (MM)
The "agent of the Underworld," C.W. Saturn is purely evil and appears to be demonic in nature, being "neither man nor woman, not animal, vegetable, mineral, or energy." He serves his master, Samael, who sits upon the throne "of heinous authority; the centerpoint of Creation's evil." Throughout history, Saturn has been responsible for some of the worst events in humankind, including indirect responsibility for the death of Abraham Lincoln.
In 1981 Saturn is dispatched as an "agent of Hell on earth" by Samael to ruin the moral fabric that comprises Superman's identity. He finds passage to earth through a dimensional tear created by a Lex Luthor prison escape, and upon arrival possesses the body of young Kristin Wells (see Superwoman), challenging Superman to forsake his sacred oath and kill her.
Saturn fails in his attempt to get the best of Superman, and each year Superman's victory over evil is commemorated on the third Monday in May, the holiday known as Miracle Monday.