This surely has to rank as one of the great "shorts" of all time. Released by MGM at the perfect time - in 1939, with the world poised on the brink of the Second World War - the cartoon portrays a family of squirrels living in an era after humanity has wiped itself out in war, as Grampa Squirrel (voices by Mel Blanc, who would of course become most famous as the voice of Bugs Bunny) attempts to explain to two babies on Christmas Eve why the Christmas song being sung says "peace on earth; goodwill to men." "What are men?" ask the babies, and Grampa Squirrel relates a story that should make all human beings squirm at our hypocrisy as he explains how humans killed each other off, and then relates the discovery by the animals who survived of a book that has a set of rules including "thou shalt not kill."
It's simplicity probably makes this all the more thought-provoking.
It's simplicity probably makes this all the more thought-provoking.