A common indulgence of the horror movie is the Gypsy Curse laid down by the stereotypical Roma (often an old woman).
These curses come as a unique brand. They'll be done out of vengeance (usually to be seen as a Disproportionate Retribution, at least from the victim's point of view) but also as some Laser-Guided Karma that's being used as a morality tale. Hey kids, don't do that nasty deed because otherwise, one day, you might do it to someone who'll go totally apeshit and curse you!
On the other hand, even when being used for that Space Whale Aesop, there seems to be a law of conservation of Gypsy Curses. The cursed person will find properly getting rid of the curse impossible but there will be some rule that allows them to transfer the curse onto somebody else like it's a forged banknote. As soon as the character finds this out, expect to have the next scene full of the most adorable, innocent looking people in the world. This is all part and parcel of the crazy, traditionalist, demonic disingenuation of the Roma portraying them as revenge focused, not justice focused, uncaring of collateral damage and inspiring selfishness in others (i.e., it's kinda racist). It doesn't help that they're often Karma Houdinis, escaping any repercussion for their actions... or even benefiting!
Also, don't ask about why these Romani slinging out curses are always portrayed as impoverished and homeless despite possessing amazing magical powers.
Sub Trope of Curse.
The greedy and gluttonous Billy Halleck runs over a gypsy woman while receiving a hand-job from his wife while driving. He's cursed to waste away no matter what he eats, a curse to mock his greedy nature. However, these gypsies discover the problem with cursing someone who really is enough of a douche to deserve it, when he sics the mob on them to force them to remove it. The curse ends up getting encased within a pie.
The judge who acquitted Halleck and the police chief who soft-pedaled the charges against him and kicked the gypsies out of the town are also cursed. The former has scales grow on his skin, the latter gets horrifyingly extreme case of acne. They both commit suicide.
Drag Me to Hell has a loan officer who refuses to extend a mortgage for the third time damned to spend all of eternity in hell.
In ParaNorman, Norman's town focuses most of its publicity on this. Back in the 17-18th century, a witch condemned to death cursed the dead to rise from the grave every year, on the anniversary of her death. But then it's subverted in that the witch wasn't cursing all the dead - just the people who sentenced her. Furthermore, it wasn't to punish the town, it was to punish the very people she was raising, by forcing them to go through what she went through - unjust violence because of fear.
A group of friends accidentally run over a Gypsy woman with their RV in Roadkill. Before she dies, the woman summons a giant bird to stalk and kill them all in order to avenge her death.
Holes had a gypsy curse / Hereditary Curse combo. However it was a condition of a deal that was broken by the cursed member. As soon as it was inadvertently fulfilled by descendants of the participants in said deal, the entire family was showered with good luck and fortune.
In HP Lovecraft's Short Story "The Cats of Ulthar", the curse of a mysterious travelling people causes the eponymous cats to take vengeance on an old couple that kills cats for fun. The mysterious travellers are implied to come from Egypt, making them literal 'Gypsies'.
Hey, a Buffy the Vampire Slayer example! Angel's soul is a result of him killing a very important girl in the gypsy hierarchy. It may seem like he's Cursed with Awesome - except that, before, he was a gleeful killer, but now he's wracked with guilt and a fear of ever being truly happy, since, if he is, he loses his soul and becomes the monster again. Of course, when that did happen, he ended up killing another couple of highly important gypsies, so maybe they regret that condition.
Played with on Top Gear when the presenters visit Romania.
Jeremy Clarkson: [pointing at his much shorter co-presenter Richard Hammond] Did you shrink that man, gypsies?
The Saturday Night Live Digital Short "The Curse": A businessman (Andy Samberg) is cursed by a homeless gypsy (Fred Armisen) after he accidentally steps on his sacred talisman. The curse in question causes everything he does to be interrupted by a shirtless man called Sergio (Jon "Mr. Fanservice" Hamm) bursting through the wall while playing a sexy saxophone solo.
A Romani woman in Murdoch Mysteries puts a Gypsy Curse on Inspector Brackenreid when he arrests the men of the clan for a crime they didn't commit, although it's not clear how much she takes it seriously, and how much she's just playing into the stereotype. The curse is that he will never succeed in his political ambitions, and by the end of the episode he's abandoned his political ambitions, which suprises her when she offers to remove it.
Married... with Children: Four centuries ago, in an English village named "Lower Uncton", a blacksmith named Shamus McBundy insulted a witch who, in Disproportionate Retribution, cursed the town into total darkness until Shamus and all of his male descendants died within the limits of the village. Shamus, being practically as polite to her as Al is with the fat ladies who enter Gary's shoe store, asked the witch if she'd float over the town to block sunlight. She cursed his feet into sweating for this. In present time, Al and Bud are (or so it's believed by the people of Lower Uncton) Shamus' last male descendants and they lure him into the village. Meanwhile, people from neighboring village Upper Uncton want the Bundys to be killed anywhere outside Lower Uncton so they'll continue prospering as a tourist attraction. The two villages eventually made a deal: Al would duel against Igor (the witch's descendant) and they'd film it all. Al fought dirty and won, which somehow ended the curse, much to the displeasure of the Upper Unctoners (no longer able to attract tourists) and even the Lower Unctoners (who dislike the fact everyone can now see they have no plantations). That's right, the very same people who spent practically a whole three-episode arc trying to get the Bundys killed within the limits of their town to break a curse didn't like to see it broken. Also, they didn't like the fact they couldn't sell the video of Al winning the fight.
Dr. Rudolph van Richten in the Ravenloft setting was cursed by the Vistani "to live forever among monsters and see all whom you love die by them". But then, van Richten himself cursed this whole tribe to be targetted by undead... and didn't know about either curse until many years later the sole survivor told him so. It turned out that curses invoked by Vistani aren't so special, but they have some traditional guidelines and a better chance that the curse will work.
In fact, this happens a lot in the Ravenloft campaign. A good rule of thumb while you're there is, don't make the Vistani angry at you.
In Psychonauts, the main protagonist Raz's circus family is said to have been cursed by psychic gypsies to die in water. This is used to explain why Raz's dad hates psychics and is used to justify the Super Drowning Skills enacted by the Hand of Galochio.
In Quest For Glory IV, a gypsy is captured by the superstitious townsfolk and accused of being a werewolf and killing a town member. If you don't save him from being burned at the stake, he will curse you and everyone in the town with his last breath, resulting in game over. After clearing his name, you find out that he really was a werewolf.
In Gabriel Knight: The Beast Within, Grace discovers that the source of the werewolf curse that Gabriel is investigating stems from a gypsy curse. After Baron von Ralick rapes a young gypsy girl, an old woman of the tribe curses him with lycanthropy.
Killing Madame Toussaud in Arcanum will permenantly penalize your character's charisma.
Invoked in one of the missions of Assassins Creed Revelations, in which Ezio must discreetly assassinate (specifically, with poison) Templars who try to take the local Romanies' money chest so that they'll think the chest itself is "cursed" and be too scared to try to steal it.
Lilah was cursed (as a newborn) by an old Gypsy woman her parents accidentally ran down on a rain-slicked country road (on their way home from the hospital with baby Lilah). She cursed Lilah to have any man who falls for her suffer the same fate as the most prominent man who also bore the name. Her parents saw no need to tell Lilah about this... until she started dating a boy named "Jesus." Oh, and Sam (the other half to the title)? His name is short for "Samson." Lilah is short for "Delilah".
This is turning out (so far) to be Cursed with Awesome for those effected by Lilah's curse. Sam gains Super Strength and super toughness (enough to get hit by a speeding car with nothing more than light bruising). We're not told explicitly what happened to Jesus; only that he rose from the dead three days later and is now a Physical God.
Ozy from Ozy And Millie has a gypsy curse running in his family that makes his hair fall out every year. (Or not. Maybe it's just his father inventing this.) His father being a dragon, he is the first family member to have fur, so the curse hadn't had effect before.
The trope is inverted in Rasputin Barxotka when a Russian witch pretending to be a gypsy, puts a bloodline extinguishing curse on Gurkha Basma and his Romani family, to retaliate against the murder of her husband.
In Survival of the FittestSpin-OffThe Program, Durriken Lovel comes from a Romani family. The family legend is that the youngest born child of each generation is cursed to have horrible luck. Durriken is the youngest of his siblings, and then his name gets called out on Announcement Day...
In a Treehouse of Horror episode of The Simpsons, Homer receives a stereotypical gypsy curse that brings misery on all those around him after trashing a fortune teller's office. He gets rid of it by attacking her with a leprechaun. The gypsy and the leprechaun then proceed to have sex in front of Homer. The episode ends with them getting married by Yoda, where they proceed to have sex on the altar...It was a Treehouse of Horror episode, okay? WEIRD shit happens during those.
Happens in Action League Now in a parody of Thinner. Basically, a gypsy curses the Chief by muttering the word "fatter". He gains an uncontrollable appetite until he basically becomes a bowling ball with a head and limbs. Eventually, he explodes and turns back to normal.
In Sponge Bob Square Pants, a hagfish curses the Krusty Krab after being refused service. Mr. Krabs dismisses it at first, but then no one comes into the Krusty Krab and he starts losing money. He and SpongeBob eventually convince the hagfish to remove the curse... which she does by taking down a "Closed" sign she had posted in front.
Mr. Krabs: That's it? That's the curse?
Hagfish: I don't waste good curses on bottom feeders like you.
In Dave The Barbarian, "the Nomads", known for being extremely touchy, curse the main character's homeland with a heatwave after Dave asks if their fishcakes are fresh. Then at the end of the episode, Dave accidentally smacks them with the door and they cast another curse that ends the show.
Johnny Bravo: Johnny is cursed to shrink in size by a gypsy he angered. In another episode, Johnny's attempts to flirt with a gypsy fortune teller get him cursed to spend a day as a woman.
Mentioned in passing in Archer, when Cheryl's puking her guts out: "I'm going to die in a toilet! Just like the gypsy said!"
One episode of Timon & Pumbaa has a gypsy put a curse on Timon after he tried to eat her (she was a bug). While Pumbaa was worried, Timon didn't believe in the curse...until the next day when he woke up as a bug.
Garfield and Friends: When Garfield destroyed a gypsy's gig, she cursed him into becoming a wolf under the full moon. Even the gypsy didn't believe it would work until Jon confirmed it. She eventually ended the curse, but then Garfield retaliated by turning her into something even more horrifying: a mime.
A common legend in English Football is that a group of gypsies, angry about being ejected from their land so that Derby County could build their ground, cursed the club never to win a trophy. The club then went on to come agonisingly close on several occasions, but losing either in the semifinal or the final (In one final, they lost 6-0). However, after the club reached the FA Cup final in 1946, an agreement between the club and the gypsies was reached and the curse was lifted. They won.
There's also the story that a woman claimed to have put a similar curse on Nottingham Forest (maybe she was a Derby fan...), but it clearly failed, since it was just before they won the European Cup two years in a row.