Fred Gwynne (Herman) later wrote and illustrated the children's book Pondlarker, spoofing the frog prince archetype.
The boy whom Marilyn brings home at the beginning of the episode was played by Jackie Coogan Jr. His father, Jackie Coogan, played Uncle Fester on The Addams Family (1964) which was running on ABC for the same years that The Munsters ran on CBS.
When one of the cops says, "Giant green monsters need their sleep so they can put all those peas into the can!", he's referring to the Green Giant brand of canned peas.
Dave Willock, the shorter policeman, announced 17 episodes of Whacky Races (1968).