Reunion Revenge

During a Class Reunion, someone who was picked on, teased or outright abused during their high school years takes their revenge on their (many) erstwhile tormentors, one at a time, and usually fatally. The main character(s) may be mistaken for members of the offending group (or may have been unwitting accomplices), but more often are uninvolved bystanders until the first death. Naturally, the rest of the reunion is spent figuring out who the culprit (and/or who their next victim) is.

A version of the Nasty Party. Often takes the form of Ten Little Murder Victims.

Anime and Manga

 * Karakurizoushi Ayatsuri Sakon had one of these involving a school's puppetry club.

Comic Books

 * In a Donald Duck comic book story, Donald plans to settle some scores with some bullies at a class reunion by training to beat them up. However, Daisy Duck, disgusted at this puerile behaviour, talks him out of it. It turns out that was a good thing considering that Donald learns to his consternation that his former bullies still tower over him and he would have been way over his head starting a fight.
 * Donald never has luck against bullies.
 * In Empowered, most of the superheroes are outright jackasses who often pick on the D-listers. So it should come as no surprise that one of them finally snapped at a superhero get-together. There's also a Not So Different moment with the title character, who's one of the most pitiful, picked-on superheroes imaginable.

Film

 * The entire plot of slasher flick Slaughter High, where a nerd named Marty Rantzen tries to get revenge on former classmates and bullies who accidentally and horribly disfigured him through a series of escalating pranks.
 * National Lampoon's Class Reunion (1982) built an entire movie around this trope and played it for laughs.
 * Rose of Death
 * Class Reunion Massacre

Literature

 * Jon Stewart (the same one from The Daily Show) once wrote a short story involving a man who creates an Artificial Human specifically to take revenge on the rest of his class at his high school reunion. On arriving at the reunion, however, the man discovers that almost the entire class had the same idea; aside from a small group of terrified people in formalwear, the reunion has degenerated in a fight to the death between those seeking revenge. He gives up and goes home, monster in tow.
 * Pawing Through the Past by Rita Mae Brown and Sneaky Pie Brown.
 * Ben Elton's Past Mortem
 * Unsound Variations from George R.R. Martin has one of these, though it's not a full high school reunion, the man simply invited three of his sort of friends from high school. Also, instead of being an opportunity for revenge it's the culmination of it. He reveals to them that he invented a device capable of Mental Time Travel and how he used his knowledge of the future to ruin their lives. His plan to crush them completely like this backfires to about the furthest possible extent. Instead of despairing they gain new hope, since they now know for a fact that they would have been very successful had not a crazy time traveler devoted at least two lifetimes to wrecking their careers. On realizing this he uses the machine again, which means bad news for an alternate reality them, but at least means he's no longer a danger in their current reality.
 * In The Demon Princes final volume, The Book of Dreams, supercriminal Howard Alan Treesong pays an amusing (for him) visit to his high-school reunion.
 * The plot of The Diamond Brothers book I Know What You Did Last Wednesday is a group of old classmates being invited to a reunion on a remote island being murdered one by one. A parody in that.

Live Action TV

 * Lois had a class reunion on Lois and Clark in which a classmate who was picked on takes her revenge on the popular people.
 * The Sean Cullen Christmas Special had, throughout the evening, an old schoolmate trying to kill Sean for taking the last place in the orienteering club. But then it turned out that Sean had never joined the club, and the other guy had spent his whole life chasing the wrong man.
 * In an episode of the sitcom Taxi, Louie lets Bobby the actor impersonate him at his high school reunion, playing a handsome "full-sized" version of him and getting (non-violent) revenge on all the class's Beautiful People. "Yeah, I shot up in college. It was written up in all the medical journals."
 * An episode of CSI: Miami had a football star (and former Jerk Jock) killed by someone who he
 * Inverted in the Designing Women episode "They Shoot Fat Women, Don't They?", where Delta Burke's ex-beauty queen Suzanne Sugarbaker is mocked at her high school reunion for being fat. The episode is also a Very Special Episode touching on the topics of weight prejudice and world hunger.

Music

 * The music video of Bowling for Soup's High School Never Ends consists of various people pranking younger versions of the band's members during their school days, and how the band got even with them during their reunion.

Tabletop Games

 * Horrible, horrible version in Exalted - one of the Deathlords, Eye And Seven Despairs, was Driven to Suicide during his life as an Exalt by the rest of his Circle. He's since developed a twisted obsession with tormenting the Shards they were bonded to (of which he has three of the four) that is occupying significantly more of his attention than his actual job, namely destroying the world.
 * To the point where The Starscream is looked upon as higher on the totem pole then he is.
 * Also, in Exalted, Autochthon built the Exalted so he could kill his brothers and sisters that picked on him and destroyed his inventions. So he creates the Exalts who kill the other Primordials, or mutilate them and imprison them in their king's own body. Talk about overreaction. Of course, given how dickish they really were, this is not that monstrous, from a certain point of view.

Web Comics

 * Helen B. Narbon plans to pull one of those during her high-school reunion in the webcomic Narbonic. However, it is eventually revealed that people didn't shun her due to disliking her - they avoided her because they were scared stiff by her easy access to mad science. Faced with this realization, Helen decides not to turn them all into gerbils after all...

Western Animation

 * Kim Possible had a variation on this. In "Attack of the Killer Bebes", Doctor Drakken (formerly Drew Lipsky) used three robotic women to kidnap three of his former college buddies, who had made fun of Drew's extremely junky "Bebe" prototypes in the mid eighties. One of the targets was Kim's father, Dr. Possible, but he failed to make the connection to his teenage arch-nemesis. He was spurred into action by the invitation to the upcoming reunion, and held them hostage at the reunion hall.
 * One of Darkwing Duck's many origin stories was remembered when Megavolt attempted revenge on the bully and the cheerleader that not only made fun of him (and bullied Drake Mallard as well), but trapped him in his experiment which ended up giving him his powers. (And theoretically frying his brain, or he might have just snapped on his own. Hard to say.) At a reunion, Megavolt tries again at a class reunion against the two bullies, who are still as contemptuous as ever. He is stopped by Darkwing and Gosalyn and the bullies learn Darkwing's true identity and are deeply impressed that Drake is a superhero. Although they promise to keep his secret, Darkwing decides to guarantee that by hypnotizing them to forget the fact while instructing them to treat Drake Mallard with some respect.
 * Batman the Animated Series villain Mary "Baby-Doll" Dahl kidnaps her former costars, but just to force them to go through the motions of the show. Except for Cousin Spunky, whom she attempts to kill with dynamite. (Who wouldn't?)
 * Danny Phantom Big Bad Vlad Masters throws a reunion to get back/murder his former best friend (who has no idea and still likes him, ironically) in order to win his best friend's wife. Thankfully, that oblivious man's son is... Danny Phantom.
 * The Venture Brothers. Mike Sorayama, an old college classmate of Doc's, dies and has his designated pallbearers (Doc, Brock, Pete White and Baron Underbheit) kidnapped. They get locked in a dungeon and learn that Sorayama was Faking the Dead and wants revenge for petty slights, all related to his one-sided crush on an attractive roommate. Underbehit tricked him into smoking cloves, to which he was allergic, making him miss a study date; Pete, the campus DJ, played an embarrassing fake dedication; Brock beat the crap out of him (and everyone else) in a drunken rage after getting kicked off the football team.
 * It's even worse for Doc; as near as he can recall, all he did was seduce a monster based off the girl in a Dungeons and Dragons game that Sorayama was DMing. Sorayama's real reason was that.
 * Johnny Bravo has combined this with Something's Different About You Now (the other typical reunion plot): Johnny wants top take revenge on a girl who always made fun of him when they were kids but it turns out that she turned into a total babe. The rest of the episode is spent agonizing whether she likes him now or she's just playing a prank on him like she used to.

Real Life

 * Bas Rutten, former UFC Heavyweight Champion and MMA Legend, was actually physically weak in High School and bullied often. When he came back for a school reunion he was a highly decorated fighter and challenged his former bullies to a fight. They all declined.