Southern humorist Lewis Grizzard told of how, when his second wife divorced him, "She took my naugahyde couch. We had to kill over 150 little naugas to get that much hide." The company that created Naugahyde, in fact, had a whole mythos about the Naugas and their hides (removed from them only to grow back, much as sheep are shorn).
Steve Martin had a similar joke in one of his routines — "How many polyesters died to make that suit?"
Bill Engvall mentions the Jimmy Dean ad listed above and cites it as the reason he can now no longer eat sausage.
Nightwing: There's these Cuban meat sandwiches at a dump called Ibano's. Linkara: Admittedly, it's hard to get the Cubans to go into the meat grinder, but....
superdickery.com presents: Squirrel Lamp ads. Yes, sir, out of a real squirrel! Not from squirrel fur, just a stuffed one.
One of the many, many things The Joker did after getting Mr. Mxyzptlk'spower was to make Chinese food from the entire population of China. "I guess someone should have yelled, 'Peking... duck!'" *burp*
Comic Strips
There's a Calvin And Hobbes cartoon where Calvin asks him mom if hamburgers are made out of people from Hamburg.
Lio ripped off the trope-naming joke once, and has had other jokes based on the same general idea.
Films — Animation
A mild example appears in A Bug's Life, where a mosquito at an insect bar orders a "Bloody Mary, O-Positive." A moment later the waiter produces a big red drop of blood...
In Rugrats In Paris, Coco LaBouche's boss tells her that the person he wants running his theme parks must have the mind of a child. Coco mutters (too quietly for him to hear — but Angelica hears it) that she thinks she has one in a jar somewhere...
Films — Live-Action
The trope first entered the mass media in The Addams Family movie, in a gag involving Girl Scout cookies.
In Sky High, the students' gym class involves a game called "Save the Citizen", which involves saving a mannequin that's being dropped into a shredder. Mr. Boy offers this reminiscence to Mr. Medulla: "Remember when we used to use real citizens?"
Malcolm Tucker: ...be gentle with them. Jamie MacDonald: Oh, you know me, Malc. Kid gloves... but made from real kids.
An example (no doubt unintentional) of Exactly What It Says on the Tin, since kid gloves ARE, or historically were, made from real kid: the leather from young goats, which is very soft.
In a trailer for Hitchcock, a biopic about the making of Psycho, Alfred Hitchcock announces at a dinner party, "Try the finger sandwiches. Made with real fingers."
Played with in one of The Naked Gun movies, when Frank Drebin just goes "give me the strongest thing you got". The barkeep brings in a burly man. "On second thought, give me a Black Russian." The barkeep has a "not-gonna-go-there" expression.
Folklore
A false urban legend tells of a company selling baby food in Africa that horrified the illiterate locals because they saw a picture of a baby on the front and assumed it to be the main ingredient.
A slightly different version: In a famine-stricken region of Africa, relief supplies were mostly in the form of canned or jarred goods with pictures of the contents on the labels. Then the baby food jars showed up, and the natives were utterly baffled.
A similar urban legend tells of a Chinese (or sometimes Korean) student in London who complains that he is unable to buy fresh dog in the supermarkets, only tinned. The tinned dog doesn't taste right so he has started catching his own.
Jokes
It is traditional to assert that the shepherd's pie in school/military canteens tastes of real shepherds.
A similar joke is made about "Sailor beef" in Swedish canteens.
Canada makes also makes a related joke about "Brownies", which are a junior branch of Girl Guides (who also sell cookies).
And there's the joke about getting thrown out of the Boy Scouts for eating brownies.
The german "Hunter Steak". Or "Zigeunerschnitzel"note Gypsy Schnitzel
There's a joke that goes: "If beef sausage is made out of beef, and pork sausage is made out of pork, what is Mennonite sausage made of?" (you can replace Mennonite with Ukrainian or any other group that has a type of sausage named after them).
The sausage example is generally used more as a sexual Double Entendre, with German and Italian being the most used
And similarly: "You know where they make mineral oil and olive oil? If you're not quiet, I'll take you where they make baby oil!"
The same joke can be made with "baby powder", or "Crime fighters fight crime, Fire fighters fight fire - so what do Freedom Fighters fight?"
A man in a restaurant complains that his shrimp salad does not have any shrimp in it. The waiter points out that there are no Italians in the Italian salad either.
A German joke goes like this: A man comes into a bakery and complains: "Your apple cakes don't contain any apples!" The baker then replies sharply: "Yes and? Dog biscuits don't contain dogs either."
"I tried a vegan diet once. Turns out vegans are harder to catch than cows."
"Are hot dogs made of real dogs?"
There is one where a Chinese person visits America and upon being offered a hot dog answers "Interesting.....that's the only part of the dog we don't eat".
Starbucks used to sell monster cookies — a type of oatmeal cookie with chocolate chips, M&Ms (or Smarties), raisins, and occasionally other things.
Bill Hicks had a bit about eating at a Vietnamese restaurant:
Bill: Hey, can I get a doggy bag? Waiter: You want another one? Bill:(beat) What the fuck did I just eat?
Should you eat your pizza with your fingers? No, you should eat your fingers separately.
Another old chestnut involves a judge questioning three people in a disturbance at the zoo. The first two said, "We were just throwing peanuts at the elephants." When the judge questioned the third person (who had a cast on his arm and was on crutches), he answered, "I'm Peanuts!"
An old Yakov Smirnoff line:
"On my first shopping trip, I saw powdered milk — you just add water, and you get milk. Then I saw powdered orange juice — you just add water, and you get orange juice. And then I saw baby powder, and I thought to my self, "What a country!"
A half-translatable sketch from German comedians Badesalz has a man sitting in the restaurant trying to cut his steak, but whenever moving the knife, the steak says "Mommy". He calls the waiter and complains about the steak, but the waiter answers: "I don't know what the problem is; didn't you order Kinderschnitzel (children schnitzel)?" In a rare example of a double punchline, the guest then replies: "I know, but why isn't it tender?"
Milton: We use only the finest baby frogs, dew picked and flown from Iraq, cleansed in finest quality spring water, lightly killed, and then sealed in a succulent Swiss quintuple smooth treble cream milk chocolate envelope and lovingly frosted with glucose. Praline: That's as maybe, it's still a frog. Milton: What else? Praline: Well, don't you even take the bones out? Milton: If we took the bones out, it wouldn't be crunchy, would it?
A better example from the same sketch is the Spring Surprise, which is a chocolate containing a coiled spring which gives the person eating it free facial piercings. It fits this example perfectly, since the ingredients are clearly printed on the box. If you don't read them, that's your own fault.
There's a background joke in the Firefly pilot: As Book approaches the ship, you can see a food stand's sign behind him advertising "Good Dogs!" No, they were not selling hot dogs. Actually, It Makes Sense in Context.
A futuristic reality-TV fashion show in Doctor Who features a face-off section. No, it's not a section comparing how well two different people carry off the same outfit, it's when they move from clothes into plastic surgery.
In the short-lived series Cafe Americain, one of the regulars is the widow of a deposed third-world dictator, constantly scheming for money with which to raise an army and retake her country. One of her plots involves getting into the ice cream business. She tries a number of disgusting flavor combinations before hitting on one everyone likes: Mint Chocolate Chip. Offhandedly, she mentions that it's made from all natural ingredients: mint, chocolate, and Chip.
Diner: Wait a minute. Who's Chip?
Joked about in an episode of Home Improvement when Jill was trying to cheer up Mark: "Would you like a piece of angel food cake? I made it myself... It was real hard to find fresh angels this time of year."
A wardrobe variant in an episode of Angel. Artode, a demon guest at Wolfram & Hart's Halloween party is wearing what appears to be a green leather jacket.
Lorne: Love the jacket, by the way. Artode: It's Pylean. Lorne: Oh, made in Pylea, my home dimension. Artode: Not made in, made from. I skinned it myself. (pause) Anybody you know?
Literature
Averted in Harry Potter. Harry is sufficiently squicked by the name Chocolate Frog that he hesitates to eat one until he's reassured that it's only chocolate in the shape of a frog, and not an actual chocolate-covered frog. This is a reference to the Python sketch, as is another Wizarding candy, Cockroach Clusters.
However, the chocolate frogs, being the product of a magical world, do in fact act like real frogs (in the movies only). The real thing (brought to you by Defictionalization) sadly does not try to escape while you eat it, but it does happen to be deliciously crunchy.
Bertie Bott's Every Flavour Beans, on the other hand, really are "every flavour". There's a reason people don't try to eat most things... The defictionalized Every Flavour Beans (made by candy mad scientists Jelly Belly) delivered on many fronts as well. Some flavors were surprisingly good (spinach, black pepper, grass, sardine); some (dirt, vomit) were even worse than they sounded. That's right, fans, the vomit-flavored jelly beans were worse than expected.
''In the corner, a vampire was drinking a bloody Mary, and going by the look on her face Mary was really getting into it.
Also, in Hell to Pay, John Taylor buys a particularly sleazy informant a glass of Angel's Urine (not a trade name) and an order of Pork Balls (serving size: 2).
The Vorkosigan Saga has the galactic standard military ration colloquially known as the rat bar. These were widely rumored to be made with real rats, and, given the state of agriculture on most of the planets, they probably were. Though Sergeant Taurra, who has eaten raw rats, would like to point out that rat bars taste better than rats.
The Alphabet Of Manliness uses this and Insane Troll Logic: What makes beef jerky so awesome? It's made from little girls. Beef jerky is made from the highest quality ingredients, and girls are made of sugar and spice and everything nice. So "highest quality ingredients" can be seen as a subset of "everything nice," so beef jerky is made out of little girls. QED.
If "highest quality ingredients" are a subset of "everything nice" then the ingredients for little girls would include beef jerky. For beef jerky to be made out of little girls "highest quality ingredients" would have to be a superset of "everything nice."
Tabletop Games
The Munchkin Cthulhu expansion The Unspeakable Vault has a Cultist T-Shirt item, made from the skin of an actual cultist.
The original Munchkin game (or one of its expansions, at least) had the item "Baby Oil", depicted as a baby in a blender.
Theater
Sweeney Todd: The Demon Barber of Fleet Street: All of the song "A Little Priest" involves this trope, but most apropos is the reference to a "humanitarian" treat of "shepherd's pie peppered with actual shepherd on top". Considering the song is a tribute to this, it would be appropriate to have the lyrics.
If you look carefully, there's some cleverly hidden Self-Deprecation in there.
Vrishika describes the nature of the "Baby Oil" she's selling:
Vrishika: Interested? It's the real thing, of course. Thousands of mewling, mortal babies went into the making of the stuff.
Vrischka also sells a chocolate mephit, which is a real mephit magically transformed into pure chocolate.
Ancient Domains of Mystery has hurthling (halfling/hobbit equivalent) cakes — cursed ones contain real hurthling and stun non-troll characters.
Alluded to in Escape From Monkey Island. Guybrush examines a bottle of "baby seal oil" and says "I'm assuming that this oil is meant to be used on baby seals, rather than..."
The Order of the Stick has one of these in strip #117, when Xykon offers to get the Monster in the Darkness a kid's meal with real kids. This one gets made into a Brick Joke by the punchline to #549, also riffing on Eats Babies.
Malack offers Durkon a cup of bloodwart tea. It turns out that the tea is not made from the herb bloodwort, but is actually a blend of blood and warts.
In Futurama: Bender's Big Score, "Torgo's Executive Powder" is ground-up network executives. It's ever so useful...
Inverted in an episode of Tiny Toon Adventures, where Elmyra thinks whale oil is made by whales rather than from whales.
Referenced in SpongeBob SquarePants. Plankton is looking for the final ingredient to his Goo-goo Gas (which should make anyone a baby). He then finds baby powder in the shopping market. Guess what.
Plankton: Is this made with real or artificial baby?
One episode of Mission Hill has the gang trying to cut back on expenses, which includes buying discount dog food. The can's label is in a foreign language, but has a picture of a dog. Judging from their pet dog's reaction, the meat isn't so much intended for dogs as made from them.
In a "Hansel and Gretel" episode of Johnny Bravo, Carl finds a cook book for German Chocolate Cake in the Witch's house. The recipe is chocolate, cake, and Germans.
Inverted in a Halloween episode of The Simpsons. A pumpkin is brought to life, and when Millhouse offers him some pumpkin bread, he assumes that it's bread made especially for a pumpkin. When Millhouse tells him that it's made out of pumpkins, he goes on a murderous rampage of revenge.