Plot

Jerry finds himself in charge of a foundling mouse called Nibbles, who is eager to steal milk from Tom's bowl and oblivious to the danger.

Jerry is awakened from a nightmare by a knock on the door: someone has left a foundling in a walnut shell with a note, giving his name as Nibbles and saying he needs lots of milk. Fortunately, there's a dish handy, but it's next to Tom. Nibbles scurries out and dives off Tom's nose, then grabs a whisker for balance, waking Tom up. Jerry grabs him just in time and they hide under the milk. Tom laps up some milk and gets Nibbles; Jerry rescues him, and they run for the hole. Next, they try a very long straw; Tom catches them and sucks Nibbles through the straw. Much chasing follows, with a pause now and then for some milk. Tom traps Jerry in a milk bottle and chases Nibbles a while; he finally corners Nibbles and spanks him with a flyswatter. Jerry is so enraged he burst out of the milk bottle and lets out a ferocious roar; he grabs Tom by the tail and thoroughly pummels him, then stands over him as Tom feeds Nibbles milk.—Jon Reeves <jreeves@imdb.com>

Jerry is asleep in his bed, dreaming of Tom catching him and knocking him on the head. The mouse wakes up and hears the knock again, to his fright, but sees it is actually a knock at his door and goes out to open it. It reveals a basket on his front door; Jerry does not notice when he peeks out the first time, and then widens his eyes in puzzlement. He pokes the basket, and it comes alive, runs in circles through Jerry's home, and then runs into a wall. Jerry pulls the blanket off the mysterious creature to reveal it is Nibbles. Wondering what to do with him, he picks up the note attached, which says, Please take care of Little Nibbles---Hes always hungry! P.S. Feed him lots of milk". Nibbles then tells Jerry he's hungry by licking his lips and rubbing his belly.

After discovering he has no food anywhere in his hole, Jerry tells Nibbles to be quiet and he tiptoes out of his hole, spotting Tom asleep by his bowl of milk. Nibbles sees the milk and runs toward it; Jerry repeatedly grabs the smaller mouse and pulls him back into the hole until he is forced to hang Nibbles on a hook by his diaper. Jerry then tells Nibbles to stay put, and goes out to the kitchen to get the milk for his younger protege.

Meanwhile, the disobedient Nibbles has caught up and passed Jerry. The bigger mouse doesn't notice until Nibbles climbs on Toms nose and jumps onto the rim of Toms bowl. Nibbles loses his balance and has to hang onto one of Toms whiskers, which causes Tom to wake up. Before the cat can open his eyes and see them, Jerry grabs Nibbles and the two land in the milk, splashing it in Tom's face. Tom, startled, looks around and sees no one, so he starts to drink his milk. Jerry and Nibbles are under the milk holding their breath until Tom unsuspectingly scoops up Nibbles with his tongue.

In horror, Jerry jumps out of the milk and bluntly opens the cat's mouth to retrieve Nibbles, which begins the chase. Jerry is holding Nibbles as he runs, but Tom starts to catch up, so Nibbles switches positions until they reach the mousehole. Nibbles is safe, but Jerry bumps his head on the wall just above the mousehole. Fortunately, Nibbles quickly pulls him into the hole before Tom crashes headfirst into the wall.

Jerry instructs Nibbles to slam a frying pan into Tom's face.Jerry then builds a pipe bridge to the milk by stringing straws together all the way into the bowl. However, Tom opens one eye to see the end of the straws land in the bowl and to hear and see milk being sucked out of his bowl. A now-hungry Tom turns the tables by grabbing the other end of the straw and drinking through it, sucking Nibbles through the straws in an attempt to eat him. Seeing the rapidly-worsening situation, Jerry squishes the very end of the straw, saving Nibbles just in time, and blows the small mouse into the mousehole.

Extremely angry, the cat chases Jerry into his hole until Tom "moves" the hole over so that Jerry crashes into the wall. Tom grabs Jerry, but Nibbles come out to make the save by hitting Toms tail with a hammer. The chase starts up again until Jerry signals for Tom to stop, while Nibbles sips and spits some milk into Tom's face.

Jerry and Nibbles hide in a closet, while Tom hammers on the door. Seeing a chance to use deception, Jerry uses a container of nail polish he discovers to disguise himself and Nibbles as a pair of black women. Emerging from the closet, Jerry, dressed in headscarf and in blackface, greets Tom: "How you doin', Mister Tom?" and beckons Nibbles, his "honey child," to hurry up. Out comes Nibbles, also in blackface and wearing a headscarf. However, the disguise is revealed when Nibbles' diaper falls down, exposing his tail and gray fur. The chase continues, eventually leading to Jerry grabbing a frying pan, holding it out straight, and Tom running face first into it and knocking himself out.

Jerry revives the cat by pulling out his tongue and smashing it with the cat's own teeth, beginning the chase again. Jerry hands the frying pan to Nibbles and allows himself to be chased through the room repeatedly. However, instead of Nibbles whacking the cat when the pair are in range, he smashes his comrade. This repeats a second time, but on the third time around, Jerry stops and points at the cat. Nibbles obliges and hits Tom square in the face, then crawls under the rug to escape along with Jerry. Tom grabs a bottle to trap the mice in as they emerge, but picks it up too soon and collects only Jerry in the bottle. Nibbles waves at him and darts back under the rug, while Tom puts a stack of books on top of the bottle and goes under the rug to get Nibbles. However, as soon as he emerges, he meets a pie placed at the exit by Nibbles.

The cat chases him until he stops at Toms bowl again and starts to drink from it. Tom, after allowing the mouse to drink briefly, grabs Nibbles. But when he opens his hands, Nibbles has crawled under Toms fur. Therefore, Tom grabs his tail and a pistol and shoots at Nibbles when he emerges from it. However, Tom has only shot his tail as Nibbles goes free. Now, the cat chases Nibbles with a flyswatter and successfully corners him. He gives him a good swat on the behind, enraging Jerry within the bottle, who runs directly through the glass and goes to inspect his friend, who is holding his behind in pain.

Tom's swat left a big red mark...and Jerry is upset about it. He faces him, pulsing with rage. Tom realizes that he has pushed him over his limit and tries to hide the flyswatter behind his back, while he lets out a massive lion roar. This makes Tom literally turn yellow with fear, and he attempts to run away, but Jerry, still fueled by anger, grabs him by the tail before he can escape, slams the cat against the floor three times, throws him behind a garbage can, and pops open the lid into the cat's face repeatedly.

Jerry is later shown standing over his shoulder with a wooden meat tenderizer in his arms, while a bandaged and bruised Tom timidly spoon-feeds milk to Nibbles.