Summary: The Yooks and the Zooks are two different kinds of, well, Seuss characters, who each have their own way of spreading butter on bread, one side up, the other side down. Soon there are goofy attempts by a hired Grandfather Yook (voiced by Charles Durning) to take on the task of stopping the Zooks from continuing on their bottom-buttered path. (imdb)

Genres: Family/Kids, Animation, Short

Country: USA

Directed By: Ralph Bakshi

Written By: Dr. Seuss

Starring: Miriam Flynn, Charles Durning, Clive Revill, Joseph Cousins, Chris Latta

More information at the Internet Movie Database