The Shadow-Thief is one of Hawkman's enemies, not Superman, but that didn't seem to matter to writer Buzz Dixon, who penned the episode, "Night of the Living Shadows", the next to last episode of the 1988 series.
Lex Luthor (Michael Bell) has developed his own shadow-suit, and created a line for a gang of thugs. Of course, with his new image as a millionaire businessman-philanthropist, Luthor can't be linked to the crimes publicly, as you'll see. Lois Lane goes undercover, and, well, chaos ensues soon after.
A Superman Family Album short follows.
Now, Lois does look kind of fetching in a shadow-suit, doesn't she? Too bad the series was cancelled, else we might've gotten a sequel, even though Luthor destroyed his suit......