For human beings, smell is the sense most directly linked to the brain, and the one that most quickly evokes memory. Therefore, it's no surprise that many characters in fiction are described as having a smell that instantly identifies them. An ex-lover may always carry the memory of her favorite perfume or his cologne, or a particularly strange character may have an equally strange, but distinct, smell to match. Another common usage is for a monster to be preceded by a certain smell, warning the heroes to its presence.
This comes up often in works featuring characters who have an enhanced sense of smell or in works with animals, since most animals rely more heavily on their sense of smell than humans do.
May overlap with Evil Smells Bad when the character is a villain.
In one episode of Lupin III, Lupin is able to figure out that a love letter sent to him, supposedly written by Fujiko, was fake because, among other reasons, the letter didn't have the faintest hint of Chanel #5 perfume.
The title character in InuYasha identifies people by scent because he is half dog demon. Early on he mistakes Kagome for Kikyo because their scents are so similar, though he quickly learns to distinguish them.
Downplayed in episode 98 of the Sailor Moon anime. Early on, Usagi and Haruka are hiding together, and Usagi notices the scent of Haruka's cologne. Later, as Sailor Moon and Sailor Uranus, they're handcuffed together by the Monster of the Day, and when they once again hide, Moon notices the same scent on Uranus. This is Moon's first clue to Uranus's identity, since at this point Uranus and Neptune have been working their own agenda separate from the other Sailor Senshi.
Bacterian from Dragon Ball has a recognizably foul stench.
Recurring Spider-Man villain Demogoblin is noted to leave a stench like sulfur thanks to the brimstone and hellfire he carries about. (He is an actual demon, after all)
In The Hard Goodbye, Marv's monologue referring to Goldie states "She smells like angels ought to smell, the perfect woman... the Goddess". This smell is later on brought up again when he meets Goldie's twin sister.
The Yellow Bastard reeks rather nasty, Hartigan pointing out the horrible smell multiple times when the Bastard is near.
In the X-Men comics, Nightcrawler's teleportation ability produces a sulfuric cloud that characters routinely complain about. It is apparently a somewhat unique smell, because he's rarely if ever confused for anyone else.
In Tremors, Graboids stink, smelling like sewage or rotten meat according to characters. This is a plot point in the first two films which occasionally clues characters in to the presence of a Graboid.
In O Brother, Where Art Thou?, Ulysses exclusively uses Dapper Dan hair pomade, and he cites its unique scent as the reason for his brand loyalty. This smell is so associated with Ulysses that the sheriff chasing him just makes his bloodhounds follow the Dapper Dan.
In 1944's The Uninvited, the manifestation of the benevolent ghost is always accompanied by the scent of mimosa blossoms. This serves as both a red-herring and a plot point when it comes to determining the ghost's identity, since one character's dead mother always wore mimosa-scented perfume.
In Anchorman, the distinctive aroma of "Sex Panther" cologne, variously described as a used diaper filled with Indian food, a turd covered in burnt hair, and Bigfoot's dick.
Captain Carrot constantly smells of armor polish and soap, to highlight his pureness.
Corporal Nobbs on the other hand, has a very strange bouquet described as a mix of cigarettes, skin cream, and old cabbage, that is instanly unforgettable to anyone who encounters it.
Beggar Foul Ole Ron has a smell that is so strange it's developed its own separate identity and sometime goes to parties on its own.
Mr. Groat from the Post Office -- a devout believer in such odd "home remedies" as putting sulfur in his socks and using a goose-grease poultice -- smells vaguely chemical, with the eye-stinging aroma of throat medicine and a hint of old potatoes.
Ahmed chews on cloves while in Ankh-Morpork, giving him a signature scent.
In the second book of the Aubrey-Maturin series, Stephen makes the mistake of purchasing a distinctive bottle of perfume for Diana, which scent never fails to remind him of her. Even when it shows up on his best friend.
On Gor each Priest-King - the Physical Gods of the world who look like giant locusts - has an individual scent, which is used as their name (they communicate via scent).
The Others in A Song of Ice and Fire are said to smell like cold. Often enough, somebody points out that cold is not a smell--but only until they have encountered an Other themselves.
Lupus of The Roman Mysteries series lost his mother as a child. He remembers that she wore lemon perfume, and always carries a handkerchief scented with lemon to remember her. When he meets up with her again at last, she wears a different perfume and he finds it jarring.
All angels and demons in Books of Pandemonium have their own, powerful signature scent, and if the PCs know what that scent is, they can use it to identify their opponents, even without superhuman ability to distinct scents.
Belgariad: Garion refers to Ce'Nedra's flower-like scent on a few occasions, and tracks her down (using his wolf form) by it once.
President Snow of The Hunger Games keeps a rose on him at all times in order to mask his peculiar breath, caused by his terminal illness. The main character thinks that he smells like "blood and roses" on every occasion she meets him.
In Harry Potter the love potion amortentia smells differently to each person based on what they're attracted to, including a scent they associate with a specific person.
Edward Cullen is said to smell like honey, lilac and sunshine.
In The Swan Kingdom, a smell of poisonous, rotting flesh is a plot point as it helps the main character draw a connection between the monster that attacked her mother and the beautiful young woman who shows up at the palace only a little while later.
Ciaphas Cain's aide Ferik Jurgen has a very persistent and unique case of BO (he's an iceworlder, so balmy temperatures make him sweat, but even in the cold he stinks) exacerbated by various skin diseases that allows Cain to know he's there even with his back turned.
In A Companion To Wolves, each wolf's true name is a unique scent.
In the novels Iron Dawn and Jericho Moon, the Egyptian sorcerer Kheperu smells uniquely-horrible: a blend of body odor, alchemical residues, and rancid unguents. It's actually intentional, as there's a price on his head in his native Egypt and he doesn't want people getting close enough to recognize him.
In The Wheel of Time, Perrin often dwells on his wife's scent, particularly the herbal soap she uses.
The third Julie of the Wolves book is from the point of view of the wolves. They always recognize Julie because her scent reminds them of willows. It also mentions that before Julie came up with her own names for the wolves, they had given each other "names" in their own minds to identify them, and they had thought of Silver as "Saxifrage" for the scented plants she liked to roll in.
In Heinlein's book Have Spacesuit Will Travel, the protagonist makes a point of mentioning the distinctive smell of the "worm-face" alien. The alien is so terrifying that the smell becomes indelibly implanted in the young man's memory, in spite of the smell not being particularly "bad".
Percy Jackson, half-blood son of Poseidon, is described at one point as always smelling of the sea.
Snistroms from The Divide series reportedly smell so bad that people around them want to throw up.
In Buffy the Vampire Slayer when Oz comes back to town he realizes that his former girlfriend Willow has been with Tara because "I can smell her on you."
Marvin is famous for the smell of his dirty diapers.
In the musical 1776 John Adams writes to his wife Abigail about how much he misses her and asks, "Do you still smell of vanilla and spring air?"
Temple of Apshai. Giant rats have a distinctive musty smell.
In The Legend of Zelda: Twilight Princess, Link in wolf form uses his heightened sense of smell to track down the next goal at hand several times throughout the game. The nature of these scents is not described, but each has a distinct colour. To wit, the four captured kids' have a yellow scent, while Ilia, Link's potential romance, has a pink scent.
Zexion of Kingdom Hearts has the odd ability of smellingdarkness, although what said odor is like is never described. In Chain of Memories, he briefly mistakes Riku's scent when he appears in the basement of Castle Oblivion for that of the Superior of Organization XIII. This is important because within Riku's darkness lies the lingering presence of "Ansem, Seeker of Darkness", the first game's Big Bad and the Heartless of Xehanort. The leader of Organization XIII Zexion alludes to is Xemnas, Xehanort's Nobody, which explains the momentary confusion.
In Grandia 2, the villain Melfice is tracked by the beastman Mareg who tends to mutter (before attacking whatever he detected it on) "This SMELL... MELFICE!!" Melfice is revealed early on to be the main character's brother. This is a problem (understatement) when they first meet Mareg, because they apparently smell alike.
The heroine has a pleasant scent which is used as the subject of a running gag by most of the characters, to the point that she considers using lab chemicals to alter it and avoid the "nice smell" comments.
Agatha has her body chemistry tangled up as part of a Grand Theft Me which involves stimulants... lots of them. This is detected by Krosp (Emperor of cats), who points out that her scent is messed up.
The Weasels, or the Wasp Eaters, detect wasps via smell (even though they are animal constructs, they are trained to react to it). The Weasels react to Tarvek's smell too - they love it, which leads to a lot of Weasels hugging him.
Lotso of Toy Story 3 is pointed out to smell like strawberries.
"The school's resident weird girl," Marcie Fleach, on Scooby-Doo! Mystery Incorporated is nicknamed Hot Dog Water by her peers because that's what she smells like. In her first appearance, Freddie explains the smell as resulting from a chemical reaction involving sweat and gingham; later, we find out that her father owns an amusement park and reuses the hot dog water for bathing. In Season 2 it becomes a plot point when Velma recognizes the smell and identifies a disguised Marcie.
In Don Bluth's Anastasia, Dowager Empress Marie dabs peppermint oil on her opera gloves. The scent triggers a memory in orphan Anya of spilling peppermint oil on the palace carpet. No matter how much servants scrubbed that spot, it continued to smell of peppermint. This statement convinces Empress Marie that Anya is, in fact, her long-lost granddaughter Princess Anastasia.
Looney Tunes character Pepe Le Pew, of course. Ordinarily skunks don't stink except when they're actually spraying, which means Pepe stinks even by skunk standards.
There is a characteristic odor that hangs around alcoholics. It's the result of the breakdown of ethanol by the liver into aldehydes that are then excreted through the sweat. It doesn't smell like alcohol; it's the characteristic odor of someone who drinks all the time.
Diabetics' sweat can take on a fruity aroma when their blood sugar is too high, as does their urine.
Five hats means that five tropers think it is ready to publish.
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it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
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