One of the most beloved of all Warner Brothers cartoons, What's Opera Doc? re-imagines the Elmer Fudd versus Bugs Bunny conflict as a German opera, complete with expressionist sets, tragic romance, and a majestic chorus of "Kill the wabbit!" Director Chuck Jones and writer Michael Maltese combine the usual wisecrack humor with a real appreciation of the classical form, crafting a loving parody of Wagner's Ring Cycle that manages to condense the massive four-opera work into a single, seven-minute story of a hunter, a rabbit, and a spear and magic helmet. Elmer takes on the Siegfried role, planning to use the magic armor to capture the rabbit. However, Bugs, as always, has countless schemes to foil Elmer -- including posing as his true love, the warrior maiden Brunhilde. When Elmer discovers this deception, however, he uses the full force of his magic to call up the power of the weather -- including winds, hurricanes, and the worst horror of all, smog. But for a few comic asides, all the dialogue is sung. Brilliant voice characterizations, wonderfully designed backgrounds, and smart writing all combine, under Jones' guidance, to create a hilarious classic.
For a take off on this cartoon see "Bohemian Whapsody"