Duvall started as a layout artist and later as a member of the story department at Walt Disney Productions.
[2] According to Jack Kinney, a director who worked at Disney for many decades, Duvall was a "charming story man" who dressed well and was "the spitting image of the Prince of Wales", but often "lived beyond his means".
[3] He was invited to Warner Bros. Cartoons in 1933 along with fellow Disney animator Tom Palmer to head up the studio in the wake of Hugh Harman and Rudolf Ising's departure.
In the event, Duvall was delayed working on other projects at Disney, and by the time he got to Warner Bros. Palmer, who directed the first Buddy cartoon, had already been fired and replaced by Friz Freleng.
[4] Animation historian Michael Barrier considers that Duvall's princely looks and "aura of sophistication" helped him get ahead.