Piggy is always hungry, thinking of food, eating, and stealing food when he can. And no matter how much he eats, he never fills up in the least bit.
When his mother leaves a pair of pies out to cool, Piggy swipes a pie from the windowsill and spins it around his finger as he eats it; he tries to eat the second pie in the same manner, but his mother catches him in time and he accidentally chomps on his bare fingers. That afternoon, his mother serves spaghetti for dinner. While the family says grace, he ties all of their spaghetti strands together, so that he can devour all the spaghetti, enough to feed a family of eight, in a single slurp! His mother scolds him, but he clearly doesn't care.
As the other pigs sleep, he is awake, in deep thought of food. The next morning, he finds himself invited into the home of a kindly, hiccuping old man. The old man asks Piggy if he is hungry and presents Piggy with a table laid out with a full-blown feast – complete with a roasted turkey. Overjoyed at the man's generosity, Piggy sits down, rubbing his stomach in anticipation. At that moment the man shoves the table of food out of Piggy's reach as the cover of the chair is pulled out from under him. A leather belt across his arms and chest straps him in place as a robotic arm swings around to take hold of his nose. The man shows himself to be some sort of mad scientist declaring, "So, it's food you want! Ha, ha! (Hic) We'll give you plenty of it!"
In the basement is the Feed-A-Matic, a bizarre machine built for the sole purpose of force-feeding hungry little kids like Piggy. The scientist rushes down to activate the controls, yelling, "So, you love food, (hic) eh?", and goes straight to his work with fiendish laughter.
The chair Piggy is strapped into first carries him to a huge vat (labeled "SUPER SOUP FEEDER") filling with gallons of soup from cans; the mechanical arm then pulls on Piggy's nose forcing his mouth open to let in a torrent of soup through a feeder shaped like a Pelton wheel but with spoons as buckets. He is then fed bananas popped out of their skins down his throat like bullets. Next to follow are stops at a gumball machine that doles out olives and at a conveyor belt of ice cream cones dispensing ice cream via a bellows. Then comes the main course, a sandwich as big as a king-sized bed (featuring the first appearance of Freleng’s "hold the onions" gag), followed by dessert dispensed from the "PIE-A-TROPE" -- pies spinning on the spindle of a converted jukebox.
Laughing maniacally, the scientist--in various montages--incessantly continues forcing food into Piggy. After an entire day of the business, the pig is returned from the basement up to the mad scientist's laboratory, transformed into an obese, food-packed ball. Bulging out of the restraints, Piggy is utterly happy. Smiling at the sight of Piggy’s obesity, the scientist pokes him twice and kindly asks "Have enough, my boy?" To which Piggy replies "Y-y-y-yes sir!" The doctor then unstraps him commenting, "Why, you're not half full!"
With the sun setting, Piggy waddles his bloated way to the door, passing by the food the scientist had laid out on the kitchen table to bait him. Looking at the turkey, he delights at the prospect of more food. He pulls off a drumstick, and after taking a bite, explodes. Or rather, he wakes up screaming in his own bed – it was just a dream. Then hearing the sound of his mother calling him to breakfast, he dashes downstairs and starts eating again with gusto, having not learned his lesson from his nightmare.
Over the years, various writers have incorporated themes and settings similar to "Pigs Is Pigs" into their works.
- Andy Panda - In "Apple Andy" (1946, Walter Lantz Studio), Andy Panda is tempted by the Devil to cross a fence to eat apples in an orchard. An angel appears to remind him of what might happen if he follows the devil. After giving in to temptation, Andy has a major nightmare. Andy dreams that he has gone to hell. He is strapped into the Feed-A-Matic machine, with the devil operating the controls. A turning lathe force-feeds green apples to him, followed by a worm shoving fistfuls of applesauce into his mouth, and a dead apple tree pouring apple cider down his throat.
- Little Audrey - Near to the end of "Butterscotch and Soda", Little Audrey eats too much candy, causing her to get very sick and the bag of candy she's gathered comes to life, singing "The Tummyache Blues". Various candy also come to life to torture Audrey by strapping her to a chair and forcing her to eat candy.
- The Gumby Show - Art Clokey did a full re-imaging of this cartoon in 1957 as part of The Gumby Show. "Grub Grabber Gumby" recast Gumby in Piggy’s role. Like Piggy, Gumby has been developing a liking for eating, and he starts the day by eating almost all the cookies on the kitchen table. Then he eats Pokey's sandwich and steals one of the pies Mrs. Applebee left out to cool (as Piggy did at the beginning). With a very full stomach, he falls asleep and later awakes to find himself in the clutches of a bipedal equine (Pokey) named "Mr. Stuff".
- Mr. Stuff: Hee, hee, hee -- so, you're the boy who likes to eat!
- Gumby: Who are you?
- Mr. Stuff: Don't worry, just call me Mr. Stuff. I'm going to do you a favor; how'd you like to have all the goodies you can hold?
Like Piggy, Gumby's face lights up with joy at the offer. Mr. Stuff is true to his word, using a conveyor belt to cram thousands of scoops of vanilla ice cream into Gumby's eagerly waiting mouth. After that, the entire contents of a tank car filled with soda pop is pumped into him, followed by a huge batch of hamburgers. This all leaves his stomach 100% swollen and bloated. But Mr. Stuff himself won't quit until Gumby is totally stuffed.
- The Lost Saucer - In the Sid and Marty Krofft series, The Lost Saucer episode, "Fatropolis," Jerry and his babysitter Alice wander into a city where fat is the law. The Mayor declares them guilty of breaking the law, and sentences them to the "Fattenarium" until they each weigh 500 pounds.
- The Simpsons - In The Simpsons fourth Halloween episode ("Treehouse of Horror IV" from the fifth season) segment "The Devil and Homer Simpson", Homer Simpson spends a day in Hell. In the "Ironic Punishment Department," a demon has Homer strapped in the Feed-A-Matic chair (recreated in exact detail) forcing him to eat "all the doughnuts in the world!" The punishment fails, however, when Homer does eat all the doughnuts in the world, and still asks for more. The demon says "I don't understand it. James Coco went mad in fifteen minutes!" According to the season five DVD set audio commentaries, series creator Matt Groening has cited the force-feeding torture scene in Pigs Is Pigs as his favorite scene in all of animation.
The animation appears crude by later Warner standards and contains some goofs.
- Piggy's design includes a set of distinctive birthmarks on him; in the beginning, he has three – one on his head, one on his rear-end, and one on his right knee. Throughout the rest of the film, he has only the ones on his head and rear-end.
- The birthmark on his head keeps changing sides -- see above pictures.
- At the end, when the scientist is letting him go, he is standing behind Piggy, yet (for a moment) his first right toe is in front of Piggy's fat stomach.
- Mrs. Hamhock speaks with a German accent through most of her scenes, but at the end, her normal accent from "At Your Service Madame" returns.
- The newer Latin Spanish dub of this cartoon as seen on DVD releases and current TV airings erroneously gave Piggy Porky Pig's stutter in his speech for reasons unknown (evidence in here: https://www.youtube.com/watch?v=XmG8Tg4DyA4)
- This film was the second (and last) featuring the Family Hamhock, which Friz Freleng had apparently intended as a series of recurring characters. They made their first appearance in "At Your Service Madame"  – this presented Mrs. Hamhock as a widow to whom her late husband had left a sizable inheritance. Rooted in the concept of morality, each of her seven children embodied one of the seven-deadly-sins; Piggy, of course, represented gluttony and was a clean freak. Leon Schlesinger didn't like this idea and Mrs. Hamhock's children would never appear again after this film. Mrs. Hamhock herself would make one last appearance in what would have been the next short in the series, "Wholly Smoke" (1938), with Porky Pig cast as her only child.
- The scene at the end of Piggy leaping out of bed to dash downstairs to breakfast was reused footage of the shot that first introduced him in "At Your Service Madame".
- "Pigs Is Pigs" is considered significant because it is the first ever appearance of Freleng's "hold the onions" gag.
- "Pigs Is Pigs", like other Blue Ribbon reissues before July 1937, retains its original end music.
- Some aspects of Piggy and his family were revived by Steven Spielberg in his Tiny Toon Adventures animated series. The character of Hamton J. Pig and his parents are a clear reflection of the Hamhocks. Like Piggy, Hamton has an incessant appetite and is a clean freak.
- A clip of this short was seen as a Toonami montage for its tenth anniversary.
- Schneider, Steve (1990). That's All Folks!: The Art of Warner Bros. Animation. Henry Holt & Co.
- Beck, Jerry and Friedwald, Will (1989): Looney Tunes and Merrie Melodies: A Complete Illustrated Guide to the Warner Bros. Cartoons. Henry Holt and Company. ISBN 0-8050-0894-2