Millionaire Elmer Fudd enters the boardroom of his multi-million-dollar company, but he isn't himself. He is hopping around on all fours and acting like a rabbit. Fudd snaps into a moment of paranoid delusion, expressing worry and fright over hunters who are out to get him. The board of directors agrees that Fudd needs help.
Soon, Elmer, now wearing a rabbit suit, is committed to the Fruit Cake Sanitarium ("It's Full of Nuts") for treatment of his apparent mental illness. A few moments later, Elmer sees Bugs Bunny walk by—in this cartoon, as in a few others, the two do not seem to be pre-acquainted—and lures him to the window with a carrot. Bugs naively says "You mean I can have that carrot if I just open the window?" Bugs goes inside, takes the bribe, and Elmer hops out the window. Bugs lies in Elmer's bed to "keep it warm for him." Bugs then notices the medicine beside him and reads the instructions (Take one teaspoon every hour, with water), but he misinterprets the instructions and ingests the spoon instead!
The Austrian hospital psychiatrist (whose name is Dr. Oro Myicin, a more obscure pun than usual for Warner Brothers) comes for Elmer, but notices Bugs in his place; Myicin, having already diagnosed Elmer with "a clear case of rabbitschenia" (a pun on both rabbit skin and schizophrenia), declares the apparent transformation of Elmer into Bugs as the "vurst case I've evah zeen!" When Myicin tries to convince Bugs he is Elmer Fudd, Bugs at first believes Myicin is identifying himself as Fudd, and politely shakes hands saying "Pleased to meet you, Mr. Fudd!" Myicin then says "No, I em naut Elmer J. Fudd, you ah Elmer J. Fudd!" Realizing the doctor's intent, Bugs presumes it is Myicin who is insane. Bugs momentary shows the audience a card with a screw and ball, then attempts to psychoanalyze the doctor instead. Irked, Myicin gives Bugs a hypnotizing "kapzule." Once it takes effect, Bugs is made to repeat, over and over, "I am Elmer J. Fudd, millionaire. I own a mansion and a yacht," gradually acquiring Elmer's speech pattern.
Myicin's programming works: Bugs Bunny leaves the sanitarium convinced he's Elmer Fudd and adopts his speech impediment, pronouncing R's and L's as W's. Myicin telephones Elmer's chauffeur ordering him not to be put off by the rabbit appearance and to get Elmer back into the lifestyle he knew before the delusion. The chauffeur tells Bugs that since it is Wednesday, he brought the hunting clothes. Bugs decides to relax by going hunting, where Elmer, still in his rabbit suit, is waiting.
It's the usual chase from there, only in reverse. Notable gags include Elmer siccing a bear on Bugs and telling him to play dead; the bear, concluding from Bugs' body odor that he is indeed dead, buries Bugs, who then falls from the underside of a cliff ledge.
In the climax, Bugs is about to capture Elmer ("No wabbit's gonna outsmawt Emmuh J. Fudd!") when a government agent (dressed in film noir G-man attire) taps Bugs on the shoulder, asking, "Pardon me, did you say you were Elmer J. Fudd?" Bugs replies with the phrase that turned him into Elmer. "Yes, I am Emmuh J. Fudd, miwwionaiwe. I own a mansion and a yacht." Bugs is then arrested for Elmer's non-payment of $300,000 (equal to $300,000 today) in back taxes, and tries in vain to explain himself, protesting, "I'm hunting a scwewy wabbit!" This time, the last line of the episode belongs to Elmer: "I may be a scwewy wabbit, but I'm not going to Owcatwaz!", as he jauntily does the bunny hop into the distance, implying that Elmer has been faking his insanity throughout the entire cartoon precisely to avoid being sentenced to prison for tax evasion.
The following scenes were edited when this cartoon was shown on ABC's The Bugs Bunny and Tweety Show:
The establishing shot of the mental hospital Elmer is committed to ("The Fruitcake Sanitarium: It's Full of Nuts") was cut, as per ABC's Standard and Practices rule at the time that forbid the mention and mocking of mental illness (which also explains why "The Duxorcist" was edited to remove Daffy calling the possessed Melissa Duck a schizophrenic and asking her if she had any other girls like her in the family and to conjure up her older sister personality).
Elmer (as Bugs) plugging his finger on Bugs' (as Elmer's) gun.
Bugs as Elmer diving headfirst into a lake, only to hit his head on an underwater rock.