BrokenSphere · CC BY-SA 3.0

Played Lieutenant Marlena Moreau in "Mirror, Mirror," the original Star Trek episode that introduced the show's evil-parallel-universe concept and gave television one of its most durable tropes, the "evil twin" goatee included. She kept working in film, television, and musicals for decades afterward, later returning to the role in the fan-made Star Trek: New Voyages.