The episode: “Bloodlust,” ep. 607
The riff: Quipped by Tom in the style of a 1950s movie title after a couple kiss messily and Mike notes “Ew, he’s unhinging his jaw.”
The explanation: Lamprey are an order of jawless fish that are common throughout the world. The most famous species such as the sea lamprey are somewhat feared and reviled for their eating method, which is to attach to the side of a fish with their sucker-like jaw of fangs and drink the blood as a parasite. They have become invasive species in many of the Great Lakes, killing fish with no natural predators. The famous episode of “The X-Files” called “The Host” featured a monster-of-the-week called “Flukeman” that was largely inspired by lampreys.
Novelty factor: I first heard about these guys when news reports discussed the problems they were posing in Lake Michigan.