Why In Cartoons They Sometimes Scream "It's A Cookbook! It's A Cookbook!"?

...back in the early 1960's there was a TV show called "The Twilight Zone" (and) one of the most popular segments was a show... showing some creatures from outer-space that came to Earth with a "Book" entitled ..."To Serve Man" ...all the People (Humans) thought it was a special book to help Mankind and bring wonderful things to Earth... (and) many of the Humans were offered a Space Ship ride back to the Planet from where these "outer space" people came from... so thousands of Humans got on their space ships and took off for this planet... eventually (someone) was able to translate what the Book (To Serve Man) really meant..(IT'S A COOK-BOOK... IT'S A COOK-BOOK !)