Woody Woodpecker first appeared in the short Knock Knock on November 25, 1940. The cartoon ostensibly stars Andy Panda and his father, Papa Panda, but it is Woody who steals the show. The woodpecker constantly pesters the two pandas, apparently just for the fun of it. Andy, meanwhile, tries to sprinkle salt on Woody's tail in the belief that this will somehow capture the bird. To Woody's surprise, Andy's attempts prevail, and Woody is taken away to the funny farm — but not before his captors prove to be crazier than he is.
The Woody of Knock Knock was designed by animator Alex Lovy. Woody's original voice actor, Mel Blanc, would stop performing the character after the first two cartoons to work exclusively for Leon Schlesinger Productions (Later renamed Warner Bros. Cartoons), producer of Warner Bros.' Looney Tunes and Merrie Melodies. At Schlesinger's, Blanc had already established the voices of two other famous "screwball" characters who preceded Woody, Daffy Duck and Bugs Bunny. Ironically, Blanc's characterization of the Woody Woodpecker laugh had originally been applied to Happy Rabbit, a Bugs Bunny predecessor, in shorts such as the aforementioned Elmer's Candid Camera, and was later transferred to Woody. Blanc's regular speaking voice for Woody was much like the early Daffy Duck, minus the lisp. Once Warner Bros. signed Blanc up to an exclusive contract, Woody's voice-over work was taken over by Ben Hardaway, who would voice the woodpecker for the rest of the decade. During that time, Blanc's "Guess Who" and laugh are archive sound.
Audiences reacted well to Knock Knock, and Lantz realized he had finally hit upon a star to replace the waning Oswald the Lucky Rabbit. Woody would go on to star in a number of films. With his innate chutzpah and brash demeanor, the character was a natural hit during World War II. His image appeared on US aircraft as nose art, and on mess halls, and audiences on the homefront watched Woody cope with familiar problems such as food shortages. The 1943 Woody cartoon The Dizzy Acrobat was nominated for the 1944Academy Award for Best Short Subject (Cartoons), which it lost to the MGM Tom and Jerry cartoon The Yankee Doodle Mouse. Woody Woodpecker's debut also marked a change in directing style for Walter Lantz studio, since the character was heavily inspired by Tex Avery-created Looney Tunes character Daffy Duck at Warner Bros, and thus Woody's cartoons intended to have a hint of Tex Avery's style and influence in terms of humor, and that what gave Walter Lantz studio its fame. Curiously enough, Avery himself never directed a Woody Woodpecker short when at the Walter Lantz studio.