The title refers to a then-recently banned boxing move, a punch to the back of the head.
The World's Championship Fight is about to begin in a gigantic boxing stadium near Bugs' hole. Tonight's fight features the battle between the Champ, "Battling McGook" (voiced by Billy Bletcher; identified as "Crusher" in subsequent cartoons), and his challenger "Dyspectic McPlaster". During the fight, Crusher doesn't even give his challenger a sporting chance at all. This prompts Bugs Bunny to heckle Crusher for playing dirty, enough for the latter to come up behind him. When Bugs calls to Crusher to pick on somebody his own size, Crusher decides Bugs will do, and throws him through the Dressing Room and into a corner of the ring. Bugs then admits it was a mistake to open his "big fat mouth".
In the ring, Crusher shows off his muscles by bulging his biceps and getting muscles on his muscles. Unimpressed, Bugs tries flexing his muscles, which are only grape sized.
The bell rings to start Round 1. Bugs comes up to Crusher pretending to give him a sporting chance. Amused at Bugs' inexperience, Crusher just punches Bugs back to his corner. Bugs charges and gets pushed back twice. Bugs then decides to pull off a little "stagety." Coming back to the center of the ring, Bugs fakes fainting. When Crusher looks over him, Bugs punches Crusher up to the ceiling. The bell then rings to finish Round 1.
While Bugs relaxes to a good book, a comfy armchair, and a radio, Crusher decides to cheat by building a brick boxing glove over his right hand. The bell then rings to start Round 2. Just as Bugs and Crusher come towards each other, Crusher punches Bugs with his brick boxing glove, sending Bugs back to his corner.
Just as Bugs is "kissing the canvas," the sportscaster starts the count, but Bugs snatches his microphone and immediately starts describing action that's not taking place, confusing Crusher long enough to trip over him. Angered, Crusher pulls off his gloves and comes to the center of the ring, which makes Bugs pull off his gloves (stuffed with horseshoes) and come to the center of the ring. The two of them wrestle, with Bugs picking Crusher up and then getting flattened by Crusher's weight. Bugs then gets himself flapped out again, and begins trying to pull Crusher's leg, while Crusher plays solitaire with cards. Knowing this is not getting him anywhere, Bugs takes a plank and breaks it, making Crusher think Bugs broke his leg. Bugs comes in disguised as a doctor and, after a fake examination, the prognosis being: "A compound fracture of the left clavichord, with complications yet", wraps up Crusher from head to toe in the bandages. Then, he punches Crusher so that Crusher bounces off the four poles of the ring, making "Tilt" flash up as in a pinball machine.
Before Round 37, Crusher sneaks over to Bugs' corner and puts axle grease in his resin box. While Crusher sneaks back to his corner, Bugs wipes his feet unknowingly in the grease. Crusher sees this, and when the bell rings to start the round, he runs over but stops immediately. Bugs is "ice skating" with the grease on his feet. He punches Crusher in the face multiple times. After spinning around, Bugs calls "Ta da da," only to have Crusher punch him in the jaw and back to his corner.
In Round 48, Crusher gets up just as the bell rings, but stops when Bugs comes in disguised as a popcorn vendor. Bugs gives Crusher a box of hot buttered popcorn, which Crusher discovers too late is explosives in disguise. It blows up in his face.
In Round 73, just as Crusher is practicing getting up from his corner, Bugs comes up and asks him to hold a giant slingshot. When Crusher wonders what is going on, Bugs stretches the rubber band back to his corner and puts a boulder in it. Then he lets go of the rubber band, so the boulder hits Crusher in the face, knocking him out and sending him falling to the canvas.
Before Round 98, Bugs is in a giant archery bow and Crusher is in a cannon. When the bell rings to start the round, Bugs fires himself from the bow and Crusher pulls the cord, firing himself from the cannon. Both just hit each other head on and stars erupt.
In Round 110, Crusher ties Bugs to a railroad track. Then he hurries up the tracks and fetches a steam train, and starts to go towards Bugs head on. All Bugs can do is start sweating and watch as the train comes closer and Crusher gloat over his intended victory.
Just when it looks like Bugs is scared as the train is going to hit Bugs, the film appears to fall out of its sprockets and then it "breaks". Bugs comes onto a solid-white screen and breaks the fourth wall by apologizing to the audience for the inconvenience, but admits the film "didn't exactly break". He then takes out a pair of scissors and gives a smirk.
- Dyspectic McPlaster looks like an emaciated, stretched version of Private Snafu.
- The gag where Bugs gets hit to the corner and comes back with encouragement for his adversary was last used in 1946's "Baseball Bugs" and will be used again in 1949's "Knights Must Fall". In addition, the beginning of the cartoon where Bugs booing and calling out on The Crusher for the latter's foul play on his rival Dyspectic McPlaster, only for The Crusher to put Bugs in the boxing ring in place of Dyspectic McPlaster was also re-used from the beginning of "Baseball Bugs".
- First appearance of Crusher and second time Bugs takes on an adversary that's bigger than he is.
- First time Bugs tries his hands at boxing.
- One of many times in a Bugs Bunny cartoon, or any Looney Tune or Merrie Melodie for that matter, to use the pinball machine message "Tilt."
- One of many times we hear a classical piece of symphony music during a cartoon.
- Bugs uses the slingshot gag again on Toro the Bull in 1953's "Bully for Bugs".
- First time an adversary ties Bugs to the railroad tracks instead of the other way round.
- The cut film gag was last used in the Daffy Duck and Porky Pig Looney Tunes My Favorite Duck, only in this cartoon, Bugs Bunny doesn't tell us how the ending of the cartoon came out, which leaves Looney Tunes fans to picture in their minds how it would end if the film wasn't cut.
- Second time voice actor Billy Bletcher uses his voice in a Bugs Bunny cartoon, and first and last time he voices Crusher.
- During production of this cartoon, Tedd Pierce and Michael Maltese originally intended to include a referee who could interact with Bugs Bunny and Crusher during the cartoon (it's unknown if he was intended to be as jolly and plump as the one from 1943's "To Duck .... or Not to Duck" or different from that character). Chuck Jones, however, decided not to include the referee in order to save production money.
- The steam locomotive (No. 1043) that Crusher is driving mirrors the articulated steam locomotives that ran on American railroads during the 1940s and 1950s, and also a 6-8-4-4-6 type engine. The number also refers to the production number of this cartoon.
- One level in the video game Bugs Bunny Rabbit Rampage has Bugs up against Crusher once again. To defeat him, Bugs has to ring the bell so Crusher thinks the match is over, then attack Crusher.
- During the scene when Bugs flies out of the dressing room in his boxing gear, his boxing gloves look more like his ordinary gloves, before they return to normal when Bugs lands in his corner.
- During the "ice skating" scene, when Bugs comes up to Crusher, he isn't wearing his boxing gloves, but when he punches Crusher in the face, the boxing gloves appear on his hands and then vanish.
- VHS - Viddy-Oh! For Kids Cartoon Festivals: Bugs Bunny Cartoon Festival Featuring "Hold the Lion, Please" (only in pal regions)
- (1988) VHS - Cartoon Moviestars: Bugs Bunny Classics: Special Collector's Edition
- (1988) LaserDisc - Cartoon Moviestars: Bugs Bunny Classics: Special Collector's Edition
- (1990) VHS - Bugs Bunny en Zijn Vrienden
- (1992) VHS - The Very Best of Bugs
- (1992) LaserDisc - The Golden Age of Looney Tunes, Vol. 2, Side 4: Chuck Jones
- (2005) DVD - Looney Tunes Golden Collection: Volume 3, Disc Four
- (2020) Streaming - HBO Max