When the Scary Surprise Party turns really scary.
In TV-Land, parties are an occasion for teenagers to go wild and Spin the Bottle, families to play Parlor Games, and psychotic hosts to massacre their guests. Then there is the Surprise Party; and 90% of the time, surprise parties in fiction will end in disaster. This might vary from something as small as someone getting humiliated or showing up naked, to something as threatening as your city getting invaded by a giant monster or the surprised man dropping dead from the shock. Can be Played for Laughs or for Drama.
A rare but not unknown variation is where the character trying to organize the party runs into some heavily abnormal trouble. In these cases the party itself will take place at the end of the episode/movie/chapter, and will be uneventful.
Another occasional variation is that the "surprised" part of the party mistakes the setup with a possible ambush and decides to strike back, meaning that the partygoers will be either 1) killed, 2) forced to duck for cover or 3) stand still in horror with a present/cake/balloon/other harmless artifact that took the full brunt of the "counter-attack" standing among them.
- One of Phil Foglio's What's New? with Phil and Dixie strips in Dragon magazine was about espionage Tabletop RPGs. Part of it explained why it was a really bad idea to throw a surprise birthday party for an undercover spy (because expecting an ambush, he barged into the room and killed everybody inside). It starts in the last panel here and concludes at the top of this one.
- Get Shorty pushes this to the funniest extreme. The scene starts with a long sequence of Mafia Boss Momo wheezing his way up a long flight of steps, and from the way it's filmed, the lack of music, and the plot thus far, the audience is naturally expected that he's going to get assassinated any minute. He opens the door to his darkened apartment, and suddenly the lights go on, revealing a surprise birthday party in his living room. Momo dies of a heart attack from the surprise.
- District 9: Wikus gets home: "I need to get to the toilet, quickly! Baby, listen I might've crapped in my pants— " "SURPRISE!"
- Cloverfield: Rob, one of the protagonists, gets a nice little going-away surprise party - and New York is promptly attacked by a massive creature bigger than the Statue of Liberty.
- The Room. Johnny's fiancee decides to come out with her affair with his best friend during the surprise birthday party she's throwing for him.
- Police Academy: Eugene Tackleberry's Establishing Character Moment is him doing his last patrol as a security guard before going to the academy, noticing that there is a room with the lights suspiciously off, and charging in with his Hand Cannon blazing, scaring the living crap out of his co-workers that were going to surprise him with a farewell party and nearly got hit.
- The Dresden Files: in Cold Days, Harry's recovery from his mostly-death in Changes ends with an invitation to a birthday party. He's lost track of the passage of time and is quite surprised to find out that it's his party. Though not as surprised as he is when the lights in a darkened room suddenly go up to reveal all manner of frightening faery beings. It turns out to be a setup by Maeve, to trick him into breaking Mab's rule against bloodshed at court. He survives that, but that was only her opening gambit: she then provokes him into a fight to the death with one of her cronies in which he mustn't draw blood or use magic.
- Dollanganger Series: This is a staple trope of V. C. Andrews, to the point where these characters really should know better than to throw parties at all.
- The Inciting Incident for the whole series: Chris Sr. never shows up to his 36th birthday party because he is killed in a car crash while driving there.
- Julia and Scotty never arrived to Scotty's 3rd birthday party thanks to Murder-Suicide.
- Julian makes a scene at Cathy's 16th birthday party, and the party's basically over after that.
- Paul's flight home from a medical convention is delayed, and he arrives home to discover that the family planned him a surprise party for his 42nd birthday, scraped it when he didn't show up, and are now annoyed with him.
- The Christmas party at the end of Petals, which ends in the culmination of Cathy's Roaring Rampage of Revenge and the house burning down.
- Bart's 25th birthday party, at which his brother gets paralyzed.
- The Christmas party in Seeds, where no one shows up.
- Friends did this three times over the years:
- In "The One Where They All Turn Thirty", Monica arrives for the surprise party stone drunk. Hilarity Ensues.
- Rachel's divorced mom and dad (who can't stand each other) arrive at her surprise birthday party; the gang are forced to split it up into two parties to make sure they don't run into each other. Again, Hilarity Ensues.
- Monica is thrown a party by Rachel and Phoebe, who regretfully inform her that none of her other friends were able to make it. Monica goes into a speech about how she'd rather spend the occasion with the two of them rather than a bunch of outsiders she doesn't care about. Cue everyone else coming out from their hiding places, murmuring "Surprise..."
- How I Met Your Mother: In a flashback, Ted breaks up with an old girlfriend on her birthday. He does it over the phone, to her answering machine. The kicker? The girl's friends and family were at the house waiting to surprise her with a party, and they all heard the whole thing. Just after the line goes dead, she walks in.
- NBC's Las Vegas: Danny gets Ed a surprise birthday cake, but as they're about to confront him with it, Ed happens to be quitting his job and punching a co-worker in the face. He then turns around and runs into the cake, sending it splat on the floor.
- According to Jim has the organizing variation. Jim goes through hell and a series of hijinks trying to make sure Cheryl is surprised.
- Firefly: The crew throw an impromptu shindig for Simon, celebrating with edible protein instead of cake. What happens next? As River puts it: "Fire..."
- Buffy was once lured to one of these by Miss Calendar. She almost makes it but ends up crashing her own party with a vampire that she's fighting. Oz, who at the time was a complete Muggle, is surprised.
Oz: Hey, did everybody see that guy just turn to dust?
- Later in season 5, we get the organizing variation; The Scoobies are trying to throw Tara one; and her Mysterious Past chooses that exact moment to catch up with her.
- Picket Fences had a scene based on the urban legend about the guy who walks into his living room and takes a huge fart before turning the lights on... and seeing all the party guests turning green.
- Canadian sketch show Bizarre had a sketch showing why it was a really bad idea to throw a surprise birthday party for a security guard. Same outcome as the Phil Foglio example above.
- The Tales from the Crypt episode "Three's a Crowd" has the protagonist walk into one of these after killing his wife and best friend because he'd mistaken their party planning for having an affair.
- In an episode of Mad About You, Jamie tells Lisa to keep Paul occupied while she sets up his surprise birthday party, resulting in Lisa giving him a sleeping pill. The rest of the scene involves Jamie and Lisa half-carrying Paul to the party, before he falls asleep face-first in the cake.
- The Two Twisted episode "Finding Frank" has a security guard's colleague disappearing and calling out desperately over his walkie-talkie. When the guard goes to find him it turns out to be a surprise retirement party but goes terribly wrong when the nervous guard overreacts, firing his gun when the lights come on, killing his wife.But as the guard is being led away, he drops a bit of paper that his colleague picks up. It's an invitation to the party with the exact time, location and everything, showing that the guard knew all along and used the party to kill his wife, framing it as accident.
- Star Trek: The Next Generation: the crew throws Worf a surprise party, but he's just come through a Negative Space Wedgie and starts shifting through parallel timelines. This first manifests as small but noticeable changes at the party, such as the cake changing flavor, a painting moving to a different wall, guests who couldn't attend suddenly being there, etc. And of course Worf is the only one to notice the changes, making him start to think he's going crazy.
- In Shadowgirls, the Alpha Bitch sets up Becca to get gang-raped at the party. And the Deep Ones starts killing people
- Zii from Ménage à 3 relates in flash-back how she once set up a "surprise 6-some" for Yuki. It did not turn out as expected, and Zii found out that Yuki's Berserk Button is male genitalia.
- In Kevin & Kell, a surprise birthday party is how the gang find out Bruno (a wolf who's had some surgical modifications) has become a herbivore. The arc starts here.
- League of Super Redundant Heroes in this strip◊. Buckaress and Good Girl set up a surprise party for Laser Pony but forget that when startled his laser Eye Beams can go off. He ends up blowing a large hole in the wall of the house.
- Bob's Birthday is an animated short centered entirely around this with Bob's wife Margaret trying to throw a surprise party for him. She keeps trying to steer Bob into the living room where all the guests are hiding, but Bob's so preoccupied with other things that Margaret never gets a chance. It won the Best Animated Short Academy Award in 1994.
- And was even made into a TV series, later.
- The Venture Bros.: The Monarch enters his cocoon lair, the lights go on and everyone yells "Surprise!!!" He cries out "Crap! An ambush!" and kills a minion with a poison dart missile before he realizes what's going on.