Razor Apples

You just came home from trick-or-treating. You pour out your candy all over the floor, looking over your hoard.

"Now, now, eat something healthy first. How about that apple Mr. Hick gave you?"

Sighing, you take a bite into the apple, only to discover that there's something painful in your bite! You spit it out to discover that the apple's full of razor blades!

A trope common in Urban Legend, this is when someone puts something sharp, pointy, or just unpleasant into someone's food. Common objects to put in are pins, needles, and razor blades. Note that this is not just for Halloween candy; this applies to all foods equally, but gifts tend to be prevalent.

Named for one of the major examples; apples filled with razor blades.

It should be noted that there has never been a recorded straight instance of this happening; the World War II example below aside, it is entirely an Urban Legend. There are documented cases of persons attempting to invoke this trope, however.

Examples of Razor Apples include:

Anime and Manga

In the first arc of Higurashi no Naku Koro ni, Rena gives Keiichi a box of rice balls. The first one he bites into contains a sewing needle. But not really. It's actually Tabasco sauce, but Keiichi's escalating paranoia has started screwing with his (and the viewer's) perceptions.
In I Luv Halloween, Finch fills an apple with razor blades after he and his friends were cheated out of their candy. He gives the apple to a cop. The result isn't pretty.

Comic Books

One of the stories in Halloween: 30 Years of Terror had Michael put razor blades in candy, For the Evulz.
Odd is on Our Side, a graphic novel based off the Odd Thomas series by Dean Koontz, has a miserly man sick of trick-or-treaters trampling his garden pass out candy laced with corn cockle seeds (a Class IV toxin). One kid dies. The worst part? The candy laced with said seeds: candy hearts, purchased on the cheap after Valentine's Day. He was such a bastard he didn't even poison good candy.

Film

The original Night of the Demons featured a frame story of this. A cranky old man is angered by children, and comes home on Halloween with a bag full of apples and razor blades. The final scene involved the old man sitting down for a breakfast of apple pie made by his wife. He only asks her after taking a few bites where she got the apples...
- Of course, Fridge Logic says that to make apple pie, you have to slice the apples.
In Trick R Treat, the Serial Killer principle puts poison in some of his candy. There's also Creepy Child Sam, who uses a razor-chocolate bar as a weapon in one scene.
- Also, as a nod to this trope, when Mr Kreeg falls down the stairs, they're littered with hypodermic needles, straight pins, shards of glass, razor blades and candy.
In Candyman, during her first exploration of the "shrine" to Candyman at Cabrini Green, Helen finds a small heap of chocolates on the floor; one of them is found to contain a razor blade.

Literature

In the Chronicles of Thomas Covenant, third book, Thomas bites into an apple with a razor blade in it.
In Slaughterhouse-Five, Paul Lazzaro boasts about killing a dog by feeding it a steak with razor-sharp pieces of a spring
In The Ghost Squad and the Halloween Conspiracy, the eponymous group of ghosts has to deal with a man trying to sabotage his brother's political campaign by spiking Halloween chocolates with rusty phonograph needles.
In Chuck Pahlaniuk's novel Rant, the main character's mother puts things like ceramic beads and tacks in all the food she cooks so that the people who are eating it have to eat it very slowly and carefully, and thus actually get a chance to enjoy the flavor, not just wolf it down.
Invoked in one of the Hammer's Slammers stories about Colonel Hammer's Psycho Sidekick Joachim Steuben; one man (despite being revolted by Joachim) says Steuben isn't really evil, just extremely loyal. A woman replies that "a razor blade in a melon" isn't evil—it's just too dangerous to be permitted to exist.

Live-Action TV

In the beginning of the Firefly episode "War Stories," the crew is indulging in a box of fresh apples Jayne bought for them, when Kaylee asks Zoe why she always cuts them with a knife instead of biting in. She relates a story from the war, where the Alliance and Independent armies had a standoff, got to talking, and the Independents mentioned they had no food. The Alliance soldiers tossed over apples—which had "Griswold" grenades in them and before anyone realized it, "there's three guys just kind of end at the ribcage."
In an episode of Monk a man plans to use poisoned candy bars to cover the murder of his wife. However, after the theft of the poison is discovered by his employers he attempts to recover all of the bars before people are killed and the poison is traced to him.
In an episode of Leverage, Sophie and Elliot are attempting to teach Parker the art of persuasion. She is told to persuade Elliot to give up his apple for her orange. She does so by claiming to have put a razor blade in the apple, just as Elliot takes a bite out of it, causing him to spit it out.
There was an episode of The Commish where someone was giving out poisoned candy, so the title Commish had his son go out trick-or-treating, which they then tested one piece at a time as it was gotten. Turned out it was a neighbor of the Commish's.
Supernatural did an episode where a man dies from razor blades in Halloween candy, in a supremely gory fashion.
A Criminal Minds episodes had the psycho of the week place LSD and Rohypnol laced sweets into the bank candy bowl. Victims had psychotics episodes of rage, which they would subsequently have completely no memory of.

Music

Insane Clown Posse seem to love this trope when mentioning Halloween. Check out "Mr. Rotten Treats" and "Halloween on Military Street" to name a couple.
Stephen Lynch's song Halloween contains the line

Razorblades hidden in Three Musketeers

Web Comics

Unsurprisingly, Saturday Morning Breakfast Cereal got in on the act.

Western Animation

An episode of The Simpsons has the police x-raying the kids Halloween candy and finding razors, syringes, and...white chocolate, to which Chief Wiggum cringes at in disgust.
Sniffles is forced to eat one in Happy Tree Friends.
Although the objects were intended to be helpful, sometimes Burger Beagle of DuckTales (1987) would eat Ma Beagle's cooking before checking it for nail files or grenades.

Theater

In Martin McDonagh's The Pillowman, a little girl is found dead after having an apple filled with razor blades shoved down her throat. Unfortunately for the protagonist, an author living in an unidentified totalitarian state, this is ripped from the text of one of his stories.

Real Life

The WWII POW autobiography The Colditz Story relates how the clique of prisoners referred to as the 'Men of Spirit' spent the little time they didn't devote to escape attempts stuffing the rotten vegetables in the kitchen waste full of old razor blades, since it was taken out of the camp to be used as pigswill in the surrounding farms. Since the German authorities regarded this as sabotage, punishable by death, this was a risky pastime.
There is at least one known case of this being done to a child's Halloween candy and the kid ending up dead; on testing, several of the Pixie Stix had been poisoned (and other treats may have been tampered with as well). However, it turned out that the father of the child had killed his son and had planted the tampered candy to try and cover his tracks so that he could collect on the life insurance.
- In another case, a child died of candy apparently laced with heroin, but police found that the child had actually died after getting into his uncle's drug stash. Both cases are discussed on Snopes.com as well as other cases which were initially thought to involve Halloween poisonings. The presence of foreign objects in candy, including needles, has occasionally been shown as true, but only in isolated cases.
Fear of this causes some communities to go to extremes like x-raying the kids' candy. Of course, some parents choose for a more low-tech solution like not letting the kids eat anything that's clearly homemade and making sure none of the store-bought candy looks like it's been tampered with.
In Newfoundland, Canada, it was a common practice for people celebrating Shrove Tuesday (Pancake Day) to put items in the pancakes—usually coins, but sometimes thimbles, rings, or needles. Obviously this necessitates eating the pancake very carefully—you don't want to bite into a coin, not to mention the needle.
A taiwanese fanartist in the Undertale fandom received cookies filled with needles in a convention, apparently as retaliation over the artist drawing a popular if controversial ship.