The character Dan "Terrible" Turpin was visually modeled after the character's creator, Jack Kirby. His first appearance in the episode "Tools of the Trade" also marks the first series appearance of "The Fourth World" characters and concepts that were Jack Kirby's major modern DC Comics creations.
Michael Ironside (Darkseid) later played Lois' father, General Sam Lane, in three episodes of Smallville (2001), and Darkseid is the "big bad" of the show's final season.