When a duck hatches from the egg underneath Tom, the newborn (Little Quacker) is convinced Tom is his mother. Tom would like to eat the duckling; Jerry is determined to keep that from happening.
Spike explains to his son the rules of being a dog: 1: be man's best friend (begging, lying at feet); 2: bury bones; 3: chase cats. Just then, Tom (and Jerry) run by, offering the perfect practice subject. Spike lectures Tom to be scared by the pup or else; Jerry overhears, and is soon doing his best dog impersonation, while Tom works on various strategies to neutralize Tyke
Tom and Jerry need to repeatedly come to the rescue when a teenage babysitter, supposed to be looking after the baby, is more interested in talking on the telephone than in paying attention to the baby who keeps crawling away.
Tom drowns in a lake and sinks to the bottom. There, he finds a mermouse, which he tries to capture and eat.
Tom has plans to take a nice long nap in a hammock, but Jerry has gotten there first and is snoozing happily, so the two fight it out to see who gets to sleep there.
After Tom's mistress orders him to clean up the mess he made while chasing Jerry, Tom spies an ad for a cat needed as companion to an old lady. Tom leaves his current home for what he anticipates will be a better life, only to discover the old lady is a witch.
Tom filches a drumstick from a fresh-baked chicken. When Mammy is about to discover him, he hands it off to Jerry; this lets him be a hero to Mammy and still get his chicken. Jerry is miffed, and sees his chance to retaliate: Spike is very possessive of his bone. Jerry keeps stealing the bone and planting it on Tom. Finally, Jerry bores a hole in the bone, inserts a bolt, and gets Tom to swallow a magnet. The bone keeps coming back to Tom, even through a fence. Finally, as Tom runs off followed by Spike, Jerry, who's been hiding in a tin can, is also dragged along.
A baby elephant rolls off the circus train and right into Tom's bed. He quickly allies himself with Jerry, and with a rolled-up trunk and some paint, passes himself off as a giant mouse. The two then keep trading places to the bafflement of Tom.
Tom, whose appetite was whetted by a radio cooking program, wants to make a meal out of the pet goldfish. Jerry, who is friends with the fish, does what he can to thwart their feline foe.
Jerry agrees to help an escaped circus lion, whose first need is food. But first they'll have to evade Tom, who heard the news bulletin and is armed with a shotgun.
When Tom's harassment gets out of hand, Jerry writes to his Cousin Muscles, a tough inner city mouse, and asks for his help.
The kiddie radio host, Uncle Dudley, reminds his listeners that it is "Be Kind to Animals" week. Tom resolves to be kind to his mouse-nemesis, Jerry, but the cat changes his mind after sneaking a look at Jerry's diary.
Jerry and his diapered little mouse friend flood the kitchen, then use the freezer to turn it into a skating rink. Even though Tom finds a pair of ice skates, the mice have no problem outmaneuvering him.
Tom inherits $1,000,000 from an eccentric aunt on the condition that he not harm any living thing - even a mouse. And guess which mouse keeps following him around and pointing this out to him?
A moment after a bottle of white shoe polish pours on Jerry, Tom hears on the radio that a white mouse, having swallowed an explosive, has escaped from an experimental laboratory and that slightest jar of the mouse could cause it to explode and blow up the entire city. It is then that Tom notices now-white Jerry and concludes it's the escapee.
Tom sells Jerry to a local pet store that's buying white mice. Yes, Jerry's brown, but a little paint fixes that.
Jerry Mouse gets tired of living the country life and decides to head to the big city. However, the experience doesn't turn out quite like Jerry had expected.
The Bide A Wee Mouse Home has sent the orphan mouse Nibbles to spend Thanksgiving with Jerry. Unfortunately, Nibbles is always hungry.
Tom steals an egg from a mother duck's nest, but soon the resultant hatchling runs away from the cat and into a mouse hole, where it finds an able protector in Jerry.
A baby seal escapes from the circus and ends up in Jerry's backyard pool. Tom finds out soon enough, and when the circus offers a $10,000 reward, his goal is clear.