The episode: “Attack of the Eye Creatures,” ep. 418
The riff: Muttered by Joel as a deputy hands an officer a breathalyzer that looks kind of like a hand puppet.
The explanation: This seems to be a reference to the 1979 action-comedy “The In-Laws,” starring Peter Falk and Alan Arkin. In the movie, a sort of action-oriented “Odd Couple,” the pair run up at one point against an insane Central American dictator played by Richard Libertini. On his hand he has a crudely painted puppet, in the style of Senor Wences, and he talks to it as his personal adviser. The puppet is of course named “Pepe.”
Novelty factor: I’ve heard of the film before, but this reference took a fair bit of Googling to figure out.
NOTE: You can see the puppet itself at 2:23 in the trailer below.