The episode: “The Unearthly,” ep. 320
The riff: Testily spoken by Tom after John Carradine’s mad scientist character demands that a guy sits down after saying “you seem to be a bit wobbly.”
The explanation: They’re referring to a line of commercials for a series of children’s toys called Weebles, popular during the 1970s. Joel mentions the name a line earlier. Tom, meanwhile, is citing the product tagline, “Weebles wobble but they don’t fall down.” The toys were sort of like a cross between a Russian nesting down (without the interior) and a weighted top, so they would wobble and swing from side to side but not fall over. There were all sorts of products and vehicles for the Weebles, which somehow claimed to “help your kids learn about the world we live in,” according to this commercial. Not sure how exactly that was supposed to occur.
Novelty factor: I have heard the phrase “Weebles wobble but they don’t fall down” on a handful of occasions but never knew quite what it meant. It was fresh enough in my head for me to immediately recognize this reference, though.