1940 - HAPPY 75th BIRTHDAY BUGS BUNNY.
Tex Avery’s short - "The Wild Hare”
There were several earlier prototypes of the famous rabbit, white with a different voice, but this is the short that launched his career. Bugs says “Whats Up Doc?” for the first time, co-opting a line uttered by Clark Gable while chewing a carrot in the 1934 Frank Capra film “It Happened One Night”.
Interestingly, voice actor Mel Blanc was allergic to carrots, and kept a bucket nearby to spit them out after chewing. ...
I always thought that the Disney Silly Symphony "The Tortoise and the Hare" contained a Bugs prototype in the Diz rabbit. But several old-timers said to me that this wasn't so.
Still in all, the Disney short came out in 1934, years prior to "Hare". There was never any copyright battles about it, but what do you think?