Although fur historically was worn for warmth, it's also for centuries been associated with wealth and glamour. Thus some outfits have fur, just because it makes everything's more stylish, more grand, more sexy (since some folk like how soft fur feels, and how it looks wrapped around a woman, or a guy).
Fur worn for more than warmth alone has been around since perhaps as long as civilization. In Europe, it largely started in earnest when power shifted from Rome to Central and Northern Europe. This was around the time kings brought the ErmineCape to the Ermine Cape Effect. That combined with Sumptuary Laws about who could wear what kind of fur made this quite the luxury, save for the least expensive, like sheepskin.
The trope is as old as plays in the medieval era, but film is where it's most evident. One theory is that black and white films needed more sensation and went tactile. This idea is still plausible — unless it's explicitly for warmth or to mark a character, fur in fiction is almost always used to pretty up the scene (especially as part of Costume Porn). Even today, with Fur and Loathing, fake fur is often used for glamour.
At one point furs were so common they didn't provide characterisation the way they do today under the Hollywood Dress Code. The exceptions were very specific outfits, like the classic pimp coat. What fur was worn was generally chosen one of two ways. The first was reflecting whatever trends was popular for a certain demographic. The second was whatever the designer felt like.
These days furs are less common and tend to show Conspicuous Consumption. The trope now has competition from Fur and Loathing, where a woman in a fur coat is evil — the Rich Bitch, The Vamp or worse. Other characters who wear fur tend to do it for a single special episode. Also, in video games, fur shading also makes a good reason to have characters wear fur. Any ads for furs would count as Up Marketing.
Now since this is about gratuitous use of fur, it's not just any instance of wearing fur. Even if a fur is worn for warmth, it also has to be an excuse to have a nice fur in the scene to count for this trope. Thus an Inuit parka usually doesn't count, unless the parka is dwelt upon lovingly and is designed to be stylish.
A Super Trope to:
Emba Mink did a variation. Instead of stars wearing fur, they would show stars snuggling up to pretty ladies wearing fur (might have been their wives or girlfriends). The slogan: "Wrap Yourself In Something Special."
Anime and Manga
In the opening of one of the Sailor Moonmovies, Minako is trying on different clothes, and ends with showing up in a purple fur coat (also with Artemis lying around her neck). The others aren't impressed, but more because of the silly way she's acting.
In a Sick Episode where Usagi is having a fever dream, she's on a date with Mamoru, and she's wearing a Pimped Out Dress that has a neckline of white fur.
Emerald wears a couple fur coats, a black one, and a gray one.
Fay from Tsubasa Reservoir Chronicle wears a huge, luxuriant white fur overcoat—over at least two more full layers of clothing! Since he's from an ice-world, bulky fur is one of the few ways to glam up his appearance.
Her mother also wore a brown mink coat when her parents first appeared.
In Danger Girl, Abigail wears a mink coat to infiltrate a party.
In Silver Age Superman comics, Lois Lane was constantly competing with Lana Lang for Superman's affections. In this cover from an old comic, Lois goes back in time to prevent Lana and Superman from forming a romantic attachment, and just because of this trope, she's wearing a fur coat.
Broadway Melody Of 1940 had an agent who used an ermine cape (not the royal kind) as a way to get dates. It was apparently based on a Real Life Hollywood agent, just that the real version used a silver fox wrap instead.
Suzie Q: In the opening, Suzie wears a white fur wrap on the way to a dance.
A Muppet Family Christmas sends this one up. Kermit tells Miss Piggy he got her a mink for Christmas, and she's thrilled until she meets the mink — a live anthropomorphic mink named Maureen. Piggy is about to karate chop Kermit into next week, but then Maureen exclaims that she is Piggy's biggest fan, and Piggy quickly warms up to her.
That Lady In Ermine is certainly just using fur for glamor. Despite the name, the title character seems to be wearing an ermine coat, just because. It could have been a lot of things for what the plot was about. The final scene of the movie has her descendant wear a different kind of white ermine coat, that more fit that era, version at least sort of, that also had a white ermine hat and muff.
That Touch Of Mink also uses this trope just for glamor. There is a mink coat, and... it has almost nothing else to do with the plot, but it's pretty.
Many of Sonja Henie's films has her wearing fur, either as a garment or as part of her dress, including an ermine-trimmed skating dress in Wintertime, which was a replica of her dress she wore at one of her gold medal winning events.
In American Dreamer, Kathy, thinking she's Rebbecca Ryan, goes on a shopping spree, which includes several furs, which also get plenty of screentime later on.
The Bad and the Beautiful has at least one fur in each flashback. Respectively there was an ermine jacket, a dress trimmed with white fox, and a white mink wrap.
Gypsy: Notably a white rabbit coat and hat June wears for one of the acts, and a mink coat Gypsy wears that she lets her mother wear at the end. The first film version even had Gypsy wear a dress with a skirt covered entirely with white fox.
In the 1971 film Willy Wonka and the Chocolate Factory, the bratty Veruca Salt wore a white mink coat (one of four other mink coats she has) to the factory. And the actress's coat was specially made for her, since mink coats weren't commonly made in girls' sizes.
Roberta and the remake Lovely To Look At. The first has Stephanie wear a spectacular fox-trimmed jacket at the climactic Fashion Show.
Easter Parade has several fur wraps, including a long white ermine stole that Don shops for, and Nadine wears later on.
All I Want For Christmas had a number of scenes of opulent people in New York at Christmastime, so there were a number of furs, including Hallie wearing a white rabbit fur muff when she goes to correct her wish to Santa.
In Stage Door, Socialite Terry Randall wants to break into show business, and stays at a boarding house for actresses. She does bring a lot of her clothes, including a lot of her furs. She even lets her roommate, Jean, borrow her short ermine cape with the line "You may as well go to perdition in ermine. You're sure to come back in rags."
Matilda the Hun of Death Race 2000 wore a white mink jacket, and even a biker helmet covered in white mink.
Eva in Morning Glory (the 1933 film) wears a white fox cape at the end, and says she would like to buy a white ermine coat.
In CS Lewis's The Lion, the Witch, and the Wardrobe, the wardrobe contains fur coats, so the children conveniently take them for warmth. When spring comes, they shed them. At the end of the book, they feel obliged to explain to Professor Kirk what had happened to his coats.
The Widow Of Desire is a Cold War spy thriller written in The Eighties, about how a Russian furrier living in the US is murdered, and his American wife learns it was because he was involved in trying to bust apart a Soviet coup attempt. A white Russian Lynx coat even ends up being a MacGuffin.
In Bride Of The Rat God by Barbara Hambly, the would-be bride is a movie star, Christine, who has a sable coat, and chinchilla coat, and a monkey-trimmed jacket. She gives her sister-in-law, Norah, the monkey fur coat, and Norah also gets to wear Christin's chinchilla few times (the clothing equivalent of loaning a Mercedes), which she actually is glad for when the nights get cold.
Christine also wears a fur wrap on two covers of the book. One has her wearing a chinchilla wrap, and the other has her wearing a white fur wrap.
The Discworld books don't hide where fur comes from, but it accepts it as a part of life in this pseudo-medieval world. One of the most popular glamour furs is the white fur of the Vermine. There are a few digs about it for the sake of humor, such as the line, "the fur is highly prized, especially by the vermine itself", in Sourcery.
Sacher-Masoch's Venus In Furs combines this trope with a heavy dose of domme and the title character's only duty as the narrator's Mistress being to swathe herself in sumptuous furs, regardless of the temperature. Played as a kink, but referencing the historical luxury and power overtones of wearing furs.
Whateley Universe example: Rich Bitch Solange in her custom-made furs in "Ayla and the Great Shoulder Angel Conspiracy". Kodiak even thinks about getting her to wear her fur and nothing else that evening...
In Neuromancer, furs are grown from tissue on a bed of collagen, because most animals have died out, making them relatively widespread for a dystopia.
The Roald Dahl short story Mrs. Bixby and the Colonel's Coat is about an adulterous woman trying to keep the mink coat she got from her lover without raising her husband's suspicions. It was adapted into an episode of Alfred Hitchcock Presents.
The Bobbsey Twins: In the early editions of the very first book (published 1904), Nan Bobbsey — at age eight — says that all she want for Christmas is "a set of furs ... a beautiful brown set, just like Mamma's." And she gets them.
In the Xanth novel Centaur Isle, Princess Irene is given a silver-lined fur by the centaurs.
Live Action TV
Dallas has many, especially if it was thick and fluffy, like fox, lynx, or sable.
Jennifer Marlowe of WKRP in Cincinnati has some furs that she gets from giving rich men company (but not really sleeping with them, just being a dear friend). She has at least a black mink coat, a stole, and a white mink coat.
In the E True Hollywood Story episode of Tonya Harding, one of her friends mentioned that Tonya wanted a fur coat, like all the other girls she skated with, and her dad eventually saved up and bought her a little rabbit fur coat. There was then a reenactment clip showing a girl lacing her skates while wearing a white rabbit jacket.
Santa Claus's iconic outfit (shaped by newspapers and magazines throughout the 19th and early 20th centuries).
Fashion Magazines, in at least one issue in an Autumn month, will have a spread about fur fashion.
Nouvelle Vague's video for their cover of "Eisbär" ("Polar Bear") features the singer laying on a polar bear rug. This is a song that goes something like "I'd like to be a polar bear, at the cold pole." Hmm...yes, so she says as she strokes the fur.
Anne Murray wears a silver fox coat for much of the video for her song "Now & Forever".
The Jenny Lewis song "Rabbit Fur Coat" uses it as a metaphor when singing about her trouble past, but at the end does sing about the symbolic coat favorably.
Monique Van Vooren had an album "Mink in Hi-Fi", and the cover was her in a white mink wrap, surrounded by a pile of other mink clothes.
Lou Reed and the Velvet Underground did the musical version of ''Venus in Furs", where masochism goes hand-in-glove with the right sort of fetish clothing:
Downy sins of streetlight fancies Chose the costumes she shall wear; Ermine furs adorn the imperious, Severin, Severin, awaits you there
In the video for the Big Bang song "Forever With You", the girl wears a white fur jacket and hat, and the two guys wear fur-trimmed jackets.
Some magic items in Dungeons & Dragons require fur as their material, such as the "Cloak of Lordliness", which requires "the finest ermine" when made for a human princes or princess to wear.
Ashei, the lady knight, wears a mink costume on Snowpeak Mountain in The Legend Of Zelda Twilight Princess. It's justified in the sense that she's incognito as a yeti, but when she takes off the head of the costume, her expression of surprise (at meeting Link) makes her fit this trope in an adorable fashion.
Gaia Online being a dress-up site, naturally there are fur items. Even a few whose descriptions acknowledge where the fur came from... sort of.
Leopard Couture: Don't be concerned for the leopard. His license said he was a donor.
The Water tribe coats in Avatar The Last Airbender are for warmth, but stylish enough to be this trope as well. Mai's fur-trimmed robe, and Toph's fur puff balls on her headdress, definitely are this trope.
A few in The Cleveland Show, including a coat Donna wore in a Blaxploitation film she did years before, and Rallo got in trouble for wearing nothing but a mink coat and underwear for a school picture.
In one episode of The Jetsons, George and Mr. Spacely were in a competition where the prize was a mink coat, which each man wanted to give to his wife. They ended up in a tie and had a tug-of-war with the coat itself, causing it to tear. This worked out, since one wife ended up with a mink jacket and the other used the bottom half as a mink stole.
Queen Elizabeth II got a mink wrap as a gift for her wedding. She wore it, and other fur wraps, quite often going out (probably because they were light compared to all the regalia she wore). This might have influenced how the fur wrap became such a common style of fur in The Fifties.
Princess Diana even had a white mink jacket she wore a few times.
Is a common decoration for a Pimped Out Dress throughout history, whether trimming, edging, lining, or covering.
Take this description of a dress from 1742:
My lady 2 ' was in dark green velvet trimmed with ermine, and an ermine petticoat — a present from her son, but it would have better suited the slender-waisted daughter Fanny, who had a scarlet damask...
Ermine petticoats, as well as other fur petticoats, were actually a popular accessory for centuries, like in this picture from 1694, or this outfit from 1957.
Catherine The Great of Russia was born in Germany, and for when it was really cold, she also had an outfit with an ermine skirt.
When Kim Richards attended the LA premiere of the first film adaptation of Escape To Witch Mountain, she wore a "little white rabbit jacket", and when she saw lots of fans on the street, she recalled:
"I remember being a little girl, so scared... My mom said, 'Kimmy, what do you think they want?' 'I think they want to get my coat,' I didn't realize it was me."
So many red carpet events, even today, are visited by wealthy celebrities in mink and fur.
Mae West loved wearing furs in her films and real life, and bought a white rabbit, cape, and muff with her first paycheck from stagework. She also could wear dresses with thick fur at the hem, and move around fairly easily.
Robert Mondavi started his famous Napa Valley winery after he was fired from the nearby Charles Krug Winery by his own mother and brother (the Mondavi family owned and operated it). Why was he fired? He bought a mink coat for his wife after they were invited to attend a state dinner at the White House. His brother Peter accused him of embezzling money from the winery to pay for the coat, and dispute was so intense the two middle-aged men eventually got in a fistfight over it.