The film starts with one Muscles Mouse kicking the bejesus out of all the cats in "Hogan's Alley". Muscles gets a letter in the mail from his cousin Jerry, pleading for help. Muscles arrives to find Jerry cowering behind his dinner table as Tom chucks dynamite stick after dynamite stick into the mouse hole. The tables are rapidly turned as Muscles the super-mouse goes after Tom.
- Aside Glance: Jerry's triumphant smile at the camera at the end, after Tom, who thinks that Jerry is Muscles, meekly kisses Jerry's feet.
- Curb-Stomp Battle: Every fight between Muscles and any cat in the short ends this way, though the three cat thugs briefly knock Muscles across the room before getting annihilated.
- Elite Mooks: Tom recruits a gang of three intimidating tough-guy cats to take care of Muscles. Muscles beats all three of them senseless, after which Tom surrenders.
- Forcibly Formed Physique: Tom has been tossed across the room by Muscles and falls inside a vase. When Muscles spits at the vase and it breaks apart, Tom has been contorted to fit its shape, including having his arms bent like the handles.
- The Hunter Becomes the Hunted: Tom gets in a lot of trouble as soon as Muscles shows up.
- Inflating Body Gag: Muscles blows up his fist to a comically large size in order to punch Tom across the room.
- The Juggernaut: Muscles. None of Tom's tactics work and no other cat, including Tom or the three thugs, can physically match Muscles.
- Meaningful Name: He's named Muscles for a reason.
- Metronomic Man Mashing: Muscles Mouse is introduced rhythmically slamming cats back and forth by the tail in Hogan's Alley. He later does the same to Tom.
- Nice Hat: Muscles and the three tough cats all wear derby hats.
- Outside-Context Problem: It's obvious why Tom surrenders to Muscles at the end; clearly, he has no idea how to handle a mouse that resists all his tricks and can beat up any cat.
- Pint-Sized Powerhouse: Despite being a seemingly ordinary mouse, Muscles is strong enough to give any cat a run for their money.
- Punched Across the Room: Muscles inflates his hand to monster size and then punches Tom across the room and into a cuckoo clock.
- Screw This, I'm Outta Here!: After Muscles got Jerry's letter for help, he looks pissed. The cats who notice that he is heading their way ran for their lives and Butch creates a makeshift grave to hide from him. (A great indication that Tom isn't going to win.)
- Tempting Fate: Muscles and Jerry are relaxing on Toms bed, but the former notices his cousin nervously looking around for any signs of Tom, and airily says, "Relax, cousin, nothing's gonna happen." Thats when Tom drops a bowling ball on him from the attic. He comes back soon.
- Uncanny Family Resemblance: Muscles and Jerry look exactly alike. This allows Jerry to impersonate Muscles and get the advantage over a terrified Tom.