The carrot-chewing scenes are generally followed by Bugs' most well-known catchphrase, "What's up, Doc?", which was written by director Tex Avery for his first Bugs Bunny film, "A Wild Hare" (1940). Avery explained later that it was a common expression in his native Texas and that he did not think much of the phrase. When the cartoon was first screened in theaters, the "What's up, Doc?" scene generated a tremendously positive audience reaction. As a result, the scene became a recurring element in subsequent cartoons. The phrase was sometimes modified for a situation. For example, Bugs says "What's up, dogs?" to the antagonists in "A Hare Grows in Manhattan", "What's up, Duke?" to the knight in "Knight-mare Hare", and "What's up, prune-face?" to the aged Elmer in "The Old Grey Hare". He might also greet Daffy with "What's up, Duck?" He used one variation, "What's all the hub-bub, bub?" only once, in "Falling Hare". Another variation is used in "" when he greets a blaster-wielding Marvin the Martian saying "What's up, Darth?"