He introduced and/or developed several of the studio's biggest stars, including Bugs Bunny, Porky Pig, Tweety, Sylvester, Yosemite Sam (to whom he was said to bear more than a passing resemblance), Granny, and Speedy Gonzales.

While at Disney, Freleng worked on the Alice Comedies and Oswald the Lucky Rabbit cartoons for producers Margaret Winkler and Charles Mintz.

At the insistence of his sister Jean, Freleng soon moved back to California to work on the Bosko series, ultimately released under the title Looney Tunes.

Schlesinger was left with no experienced directors and therefore lured Freleng away from Harman-Ising to successfully fix cartoons directed by Tom Palmer which Warner had rejected.

The young animator rapidly became Schlesinger's top director, helming the majority of the higher-budgeted Merrie Melodies shorts during the mid-1930s, and he introduced the studio's first true post-Bosko star, Porky Pig, in the film, I Haven't Got a Hat (1935).

David DePatie, when asked about the Japanese beetle in Blue Racer in 1996, said this about Friz's view on race, "It seems like poking fun at certain ethnic groups had always spelled success.

"[18] In September 1937, Freleng left Schlesinger after accepting an increase in salary to direct for the new Metro-Goldwyn-Mayer cartoon studio headed by Fred Quimby.

The plot, which centers around Porky Pig being tricked by Daffy Duck into terminating his contract with Schlesinger to attempt a career in features, echoes Freleng's experience in moving to MGM.

Often working alongside layout artist Hawley Pratt, he also introduced or redesigned a number of Warner characters, including Yosemite Sam in 1945, the cat-and-bird duo Sylvester and Tweety in 1947, and Speedy Gonzales in 1955.

He won four Oscars during his time at Warner Bros., for the films Tweetie Pie (1947), Speedy Gonzales (1955), Birds Anonymous (1957) and Knighty Knight Bugs (1958).

Other Freleng fancies were man at war with the insect world (as in Of Thee I Sting (1946) and Ant Pasted (1953)), an inebriated stork delivering the wrong baby (in A Mouse Divided (1952), Stork Naked (1955) and Apes of Wrath (1959)), and characters marrying for money and finding themselves with a shrewish wife and a troublesome step-son (His Bitter Half (1949) and Honey's Money (1962)).

The "Hotel Friz" was featured in Racketeer Rabbit (1946) and "Frizby the Magician" was one of the acts Bugs Bunny pitched in High Diving Hare (1949).

[1] Warner Bros. Cartoons was closed in 1963, leading Freleng to take a job at Hanna-Barbera Productions as story supervisor on their first feature, Hey There, It's Yogi Bear!

The Pink Panther and the other original DePatie–Freleng series would remain in production through 1980, with new cartoons produced for simultaneous Saturday morning broadcast and United Artists theatrical release.

In 1986, Freleng stepped down and gave his position at Warner Bros. to his secretary at the time, Kathleen Helppie-Shipley, who ended up being the second-longest producer of the Looney Tunes and Merrie Melodies franchise, behind only Leon Schlesinger.

[25] The WB animated TV series The Sylvester & Tweety Mysteries, and the Looney Tunes cartoon From Hare to Eternity (which was the last one directed by Chuck Jones), were both dedicated to his memory.