A black cat is digging through garbage cans for food. He stumbles upon a row of trash cans and pulls fish skeletons out of them, salad-bar style. When he opens the last trash can, three cats pop out of it and eat the skeletons. The alley cat, angry, slams the three cats with two garbage can lids. The cat continues his search for food until he stumbles across a house with a refrigerator and imagines that there must be bottles of milk and all kinds of meat stored inside. The cat salivates and runs towards the house, but slows down and sneaks when he encounters a bulldog named Atom. The dog wakes up and spots the cat with his eye, which acts like a searchlight. The dog perks up and runs toward the cat, who quickly pulls out a bottle of sleeping pills and throws them into the canine’s mouth.
With the dog knocked out, the cat enters the house and opens the refrigerator—and finds it empty! He finds a sardine can, only to find that it only has a sign reading “Kilroy was here.” A while later, the cat has ransacked every cabinet in the kitchen and still hasn’t found a crumb of food. He grabs a can of cat food and opens it onto a plate, where he is very delighted to find that a mouse was inside! The cat tries to eat the mouse, but the rodent interrupts with “What are you trying to do, pal? Eat me?” The cat responds with “Yup.” The mouse says that the cat should “forget it” because “I’ve seen this cartoon before. And brother, believe me. If you’re smart, you won’t eat me. ‘Cause before this picture’s over, I save your life.” The cat says that he is hungry, so the mouse tells him that the next room holds a big, fat, juicy canary. The cat runs over, grabs the bird from the cage, tosses it in a bag, and brings it back to the kitchen to eat, only to find that the canary is very small and has been sick. The cat, disgusted, pushes the bird away.
The cat spots a bottle of “Jumbo Gro” on a shelf. The formula claims to make small things grow huge. The cat, after doing some literal brainstorming, decides to stick a funnel into the canary and pour the formula down its throat. Predictably, the canary grows bigger! The cat picks up the canary, who quickly increases in size. The cat brings the canary to the table, pulls the feathers off its right leg, and prepares to bite into it, only to quickly stop as he finds that the canary has grown as big as the kitchen! The cat slowly places the feathers back on the canary’s leg and runs for his life. The canary is at first bewildered, but then looks down and finds that its body is huge, so he throws himself on the cat and begins to pull his leg. The cat grabs the Jumbo Gro from the shelf and quickly drinks it. He increases in size. The canary jumps on the cat’s giant body. It feels the cat’s giant fangs, so it pulls them off the cat’s mouth. It then pulls off the cat’s nose and eyes. When it sees what is staring back, it screams and tosses the parts back on the cat’s face in a jumbled mess and runs.
The cat tosses the Jumbo Gro out the window, where it lands in a bulldog’s mouth. While the cat is chasing the canary around the neighborhood, the dog continues to drink the substance. Eventually, the bird stops by a house. The cat wonders what is up, and the bird points to an enormous bulldog. The cat becomes frightened and makes a run for it. The dog decides that he is done with the Jumbo Gro and tosses it down a chimney, where it rolls to the feet of a mouse. The dog proceeds to chase the cat and the canary. Meanwhile, the mouse drinks the Jumbo Gro and quickly grows enormous. The cat stops at a building. The dog stops and is confused, so the cat points out the even larger mouse. The dog runs away. The mouse tells the cat “I told you I’d save your life, didn’t I?” The cat thanks the mouse, who gives the cat the bottle of Jumbo Gro and leaves. Suddenly, the cat realizes that he is hungry. He sees the mouse walking away as food, so he drinks the Jumbo Gro to grow even larger than the mouse and pursues him with fork, knife and bib. The cat chases the mouse through the country until the mouse runs through a train tunnel. The cat tries to reach in, but the mouse runs out through the other side, drinks the Jumbo Gro, grows even bigger than the cat, and proceeds to pummel him. The cat drinks the Jumbo-Gro and grows even larger. The mouse takes the bottle, drinks it, and grows even larger. This continues until they drink and nothing happens. The cat and mouse shake the bottle and find that it is empty. The mouse turns to the audience and says “Ladies and gentlemen, we’re going to have to end this picture...we just ran out of this stuff.” The camera pans out to show the cat and the mouse waving to the audience while standing on Earth.
- Atom’s growls are actually the roars of Tanner, the lion featured on MGM’s three-strip Technicolor films.