The character is reading the newspaper, looking at the horoscope section. They find their sign, and read something so unbelievably horrifying that they will resort to doing anything or everything to prevent it from coming true.
They have just become a victim of the Horrorscope.
Sometimes, the efforts of preventing the horoscope from coming true will result in it coming true anyway. But more often, the character just ends up making a fool of themselves in desperate attempts to prevent the horoscope from coming true, only to find that they would have had the same results if they had done nothing at all.
Misfortune Cookie (fortune cookie characters would really rather not get as it includes a grim message or a demotivational phrase) is a related trope.
- Asterix series: Played for Laughs in Asterix and the Missing Scroll. Obelix' horoscope, as read to him by Wifix, states that he should avoid conflict and go easy on the roast boars (his Trademark Favourite Food). For a Blood Knight and Big Eater like Obelix, this news outright terrifies him. Nevertheless, he tries his best to stick to the advice, until it's revealed his horoscope was mixed up with that of Geriatrix.
- Calvin and Hobbes had a story arc involving horoscopes. While the first horoscope he read, "Many of your key policies will be implemented" wasn't bad (even though it didn't come true), his second one, "Opposite sex finds you irresistible" was very much a Horrorscope. (That one didn't come true either.)
- The trope is name-dropped in The Rum Diary. Paul is assigned to the horoscope section of the San Juan Star paper by his boss because Paul's aims as being a brutally honest journalist conflicts with the feelgood, profit-over-journalistic-integrity that the paper is going for. Paul goes at it with very little enthusiasm, at one point referring to it as a "horrorscope".
- Alexander Tagere's horoscope in Arcia Chronicles predicted that he would die within hours after his birth. He didn't, but it got worse from then on for him with lots of suffering which he faces stoically.
- In one of the Dirk Gently books, it is mentioned in passing about a horoscopist enemy of Dirk's who writes purposely bad stuff in Dirk's daily horoscope — too bad for the twelfth of the world who share Dirk's birth sign.
- Sayers and Viney's The Bad News Horoscope was a deliberate attempt to subvert the generally happy, positive, upbeat, Linda Goodman school of astrology which placed undue emphasis on all the nice things people like to read about their own star sign (and by extension themselves). In the S&V world — using exactly the same logic, reasoning, source material and astrological tradition as Goodman — the world takes on a different perspective.
- In a sketch on Monty Python's Flying Circus, a pair of Pepperpots read the daily horoscope; Scorpio is, "You will have lunch with a schoolfriend of Duane Eddy's, who will insist on whistling some of Duane's greatest instrumental hits. In the afternoon you will die, you will be buried..."
- The Vicar of Dibley: In anticipation of Hugo's wedding, Frank reads out Hugo's horoscope at a council meeting, which predicts a very happy and romantically-fulfilling day... until Geraldine points out he's got the wrong month. Hugo's actual horoscope predicts doom and disaster.
- Wizards of Waverly Place: In "Misfortune at the Beach", the kids stumble upon a "Zelzar" fortune-telling booth, and are warned that for Wizards, each fortune is very real. Max gets free ice-cream and Justin manages to attract a cute girl. Alex gets a fortune that says "Say goodbye to your life" and as such makes a deal with Zelzar that, if she gives him a day at the beach, he'll take back her fortune. After several near-death experiences and frustration, Zelzar finally agrees, he passes Alex's fortune to the next customer, a little girl... who immediately receives a giant check for a million dollars, effectively saying goodbye to her old life.
- An episode of Strange Days At Blake Holsey High had one character write one of these in the school newspaper. Unfortunately, Blake Holsey's usual brand of weirdness decides to manifest by skewing the bell curve in a way that all of these come true.
- About half of the entries in "Weird Al" Yankovic's "Your Horoscope For Today" are predictions of catastrophes and disasters, played for laughs. The other half are bizarre instructions.
Aquarius: There's travel in your future
When your tongue freezes to the back of a speeding bus
Fill that void in your pathetic life
By playing Whack-a-Mole seventeen hours a day
Pisces: Try to avoid any Virgos or Leos
With the Ebola virus
You are the true Lord of the Dance
No matter what those idiots at work say
- Mary Chapin Carpenter's "I Feel Lucky" opens with checking the horoscope and finding a warning: "The stars are stacked against you, girl, get back in bed."
- The Onion's faux horoscopes are often blackly comedic in nature.
Scorpio: Your week will be so varied, interesting, and surprising that eventually the coroner will just give up, shrug, and write "heart failure" in the spot marked "Cause of Death".
- Twitter account Sorrowscopes runs on these. About twice a week they post fake horoscopes with something of a depressing bent.
Sagittarius: When you wish upon a star, it makes no difference who you are. Because the stars dont give a shit about you.
- The occasional horoscope segments in Welcome to Night Vale are full of ominous, threatening, or at the very least bizarre messages befitting the Surreal Horror of the setting. With the exception of Scorpio, which happens to be the sign of the narrator's brother-in-law and is usually just a personal insult.
Scorpio: You are respected by your peers. You are a great thinker and leader. You wait, what is this? This is definitely not the right reading for a Scorpio, it must be a typo. I bet the stars meant to say: You should hear what theyre saying about you. Very funny things, Scorpio! Theyre saying very funny things at your expense, you jerk! Yep, thats definitely what the stars meant to say.
- The Trope Name comes from Cartoon Planet, where "Zorak's Horrorscopes" was one of the sketches, and they were basically portents of doom regardless of what sign you were under.
- The Simpsons: In Treehouse of Horror XI's story "G-G-Ghost D-D-Dad", Homer reads a horoscope saying he will die that day. Not only that, Marge's horoscope says her husband will die that day.
- The "Fortune Cookie" episode of Rocko's Modern Life features this plot, when Filburt gets a fortune cookie that says, "Bad luck and extreme misfortune will infest your pathetic soul for all eternity.". Sure enough, the rest of the episode entails the entire city burning down around Filburt. But he does win a new trailer home in the end.