influential American director of animated cartoons, primarily for the Warner Bros. and Metro-Goldwyn-Mayer (MGM) studios.

Avery's only formal art training consisted of a three-month course at the Art Institute of Chicago during the late 1920s. He began his animation career in 1929 for cartoon producer Walter Lantz (Lantz, Walter) at Universal Studios. For the next six years he worked for Lantz and freelanced his drawing and gag-writing services to other studios. In 1936 he was hired by Leon Schlesinger, the head of the Warner Bros. (Warner Brothers) animation unit, who put Avery in charge of a team of animators that included such notable names in the field as Chuck Jones (Jones, Chuck), Bob Clampett (Clampett, Robert), and Bob Cannon. As Warners did not have the resources to compete with Disney studios (Disney Company) on a technical level, Avery endeavoured to make his cartoons the funniest and best-written in the business. He increased the pacing of the films and filled them with outrageous gags. He also redesigned Porky Pig—then the studio's star character—and created Daffy Duck, whose personality of unmotivated insanity was unprecedented in cartoons. Most important, he gave a definitive personality to Bugs Bunny in his fifth film, A Wild Hare (1940), and was responsible for Bugs's immortal catchphrase “What's up, Doc?”

After a heated dispute with Schlesinger over the editing of the Bugs Bunny short Heckling Hare (1941), Avery left Warners and worked briefly for Paramount Pictures (Paramount Pictures Corporation) before being hired to head MGM (Metro-Goldwyn-Mayer, Inc.)'s animation unit in 1942. From 1942 to 1954 he created 67 cartoons for MGM, including several masterpieces of the genre such as Who Killed Who? (1943), Batty Baseball (1944), Screwball Squirrel (1944), and King-Size Canary (1947). A number of his films feature a curvaceous showgirl in revisionist fairy tales (Red Hot Riding Hood 【1943】, Little Rural Riding Hood 【1949】), a paranoiac wolf (Dumb-Hounded 【1943】, Bad Luck Blackie 【1949】), or the slow-talking dog Droopy (Northwest Hounded Police 【1946】, Droopy's Good Deed 【1951】), who served as foils for the director's brilliant takeoffs on such themes as survival, control, fear, and the film medium itself.

Avery's attitude toward animation was opposite that of Walt Disney (Disney, Walt), who favoured straightforward storytelling, classic draftsmanship, realistic narratives, and a live-action approach to the staging of action. By contrast, Avery celebrated the cartoon as a cartoon; his work never pretended to be anything but a drawing come to life. His films exhibited a love of exaggeration in his use of absurd gags presented at breakneck speed. An irreverence toward cinematic conventions pervades most of his animated films, as when characters comment on the action happening around them, sometimes by holding up a sign (“Silly, isn't he?”) or by addressing the audience directly. Avery's self-reflexive, modernist approach emphasized parody and satire, and his layered gags were held together on the screen by sheer manic energy. He brought brashness and an adult sensibility to animation that was aimed not at the family audience but toward amusing himself and his fellow animators and, by extension, all adults.

MGM eliminated Avery's animation unit in 1954, and he spent most of the rest of his career directing television commercials. During the last two years of his life, he developed gags and characters for the Hanna-Barbera (Hanna and Barbera) Studio. Avery is second only to Walt Disney in terms of his influence on American animation.