William Hanna met at least one person.
Hanna–Barbera . It was founded in 1957 by former Metro-Goldwyn-Mayer animation directors William Hanna and Joseph Barbera ( creators of Tom and Jerry ) and live-action director George Sidney in partnership with Screen Gems , a TV unit of Columbia Pictures . William Hanna . In 1937 , while working at Metro-Goldwyn-Mayer ( MGM ) , Hanna met Joseph Barbera . The two men began a collaboration that was at first best known for producing Tom and Jerry and live action/animated hybrid films .