Funnyman Al Lewis, always memorable for his stints on "Car 54" and "The Munsters", plays a nutsy and egotistical magician, with lousy ventiloquist's dummy in tow, in this rather mindless segment.
Though Lewis gets to pull faces and basically ham it up, Dr. Smith is the central character here, dominating the show as he often does, with Mumy and Cartwright as his young straight men/women. Storyline is dumbed down even more than usual, making this a difficult sit-through for an adult. Basically the silliness perpetrated by Lewis is meant as a diversion for the youngest viewers of the show, but looking back at my own childhood and tv watching habits I would suggest that a good old story about a ventriloquist and his dummy, especially a darker one (classics like "Devil Doll" come to mind) are far preferable, as long as the kid is old enough to not be prone to nightmares.