The sound of the baby drinking his milk was actually the sound of a puppy, and the sad eyes of the wolf were copied from a magazine picture of a rescued kitten.
The title of the film, and partial inspiration, came from a poem by Nazim Hikmet. The original title "The Little Grey Wolf Will Come" was rejected by censors.
Yury Norshtein worked on the film with his wife Yarbusova. He sketched the characters and scenes and Yarbusova drew the silhouettes and scenery. They always did everything by hand even after most animators began using computers.
Norshtein's technique is to use drawn or painted figures, with all of their moveable limbs and features drawn separately, and film them from above. The scenery is drawn on layers of transparent celluloid, which are placed on top of one another to create the illusion of depth. Each second of the completed movie is made of 24 stills.
Nurshtein's original proposal was a story about a poet who couldn't write. The Soviet censors were confused by the final film that bore little relation to the proposal, and grew suspicious. They almost did not allow its release.