The Worst Bakers In Equestria is all about a contest entirely built around ponies who don't merely bake badly, but who bring forth inedible abominations in the most spectacular manners possible. The contest only uses one stage at a time, but has a backup in case one becomes too damaged (or toxic) to be used.
In a direct Shout-Out to the former trope image and an inversion of the trope, Magnetism tells us "Rainbow Dash poured the milk into the bowl of cereal. Astonishingly, this time it did not catch on fire."
A Brief History of Equestria: Star-Swirl the Bearded's Winter Emergency Summit between the tribes was planned to last a week, with preparations to go on longer if necessary. The Shouting Congress, as it became known to history, lasted twenty minutes.
As opposed to her son Hurricane, Star Saber's life is just one failure after another: While her friends become high-ranking military figures, she's still a non-commissioned officer, and when she decides to have children so she could live vicariously through them, she's too old for pregnancy to happen easy, and when she does get pregnant, it's a colt, and thus pretty much unlikely to advance very far. A few decades (and a demotion) later, she tries to go the Rebellious Rebel route and not only fails spectacularly, but she's not seen as worth the effort to kill. Later still, she's 92 and still in the military, and dies defending a single crate of food. ...That was empty. Her own son describes her as an incompetent fuckwit.
In one Dashverse story, during a game of Truth or Dare, Twilight is dared to hogtie Rarity. Somehow, she ends up tying them both together.
A rather frightening one. In Human Curiosity, while the HCS's attempt to kidnap and kill off as many Nations as possible seems like it's successful, it starts to go to pieces when a massive prison break is attempted and a number of Nations escape. One of whom was the only Nation to memorize the location of every HCS base in the world (England). From there, the remaining free Nations find the escapees and use England's knowledge to storm every HCS base, freeing all the prisoners and stealing what research remains. The HCS is forced to abandon everything they've worked for and disband to survive. One of the former leaders tries to make more progress by unfreezing the Nations in stasis (they've been turned mortal and loaded with poison, in the hopes this would make it impossible to revive them). Not only does this not work at all, since the Nations just die and come back to life exactly as they were, but he dies in the process and the newly-revived Nations set about killing off the rest of the HCS.
Germany and Italy's date in ''Chasing an Empty Dream, which makes the canon Valentine's Day date look like smooth sailing. The whole thing was orchestrated by Prussia. To keep Germany from panicking, Canada borrows spy gear from America so they can give tips. Unfortunately, this means America has to stay with them to keep an eye on the stuff, and acts obnoxious the whole time. Meanwhile, Romano uses a Paper-Thin Disguise to pretend to be their waiter, wanting to spy on them and verbally abusing Germany until the manager mistakes him for a real waiter and sends him to the kitchen (Italy, of course, fails to realize who "the waiter" is). Spain bursts into the restaurant with a battle axe Romano asked him to bring, leading the other diners to think he's a terrorist and causing America to try to blindly play the hero. At this point, England shows up with his hair and eyebrows dyed pink, to yell at America. Canada gets rid of America by stealing his glasses, England is gotten rid of by having France come in (completely naked) and carry him off, and Spain has to run off with Romano. And it ends on a very sad note, as Germany confesses to Italy that he used to be the Holy Roman Empire, only for Italy to become upset and reject him.
In the Slash FicSeeing, Believing, Dreaming, Deceiving during a karaoke contest at Hogwarts, Lucius Malfoy gets up on stage while drunk and attempts to woo Remus Lupin by serenading him with an off-key rendition of Warren Zevon's "Werewolves of London." This goes about as well as you'd expect.
In Blue Sky, Wheatley attempts to make bread. What results is most emphatically not bread, in every possible way something can be not bread, and violates several laws of geometry, thermodynamics, and physics in the process.
In the Facing The Future Series story Stolen Years, Jack designed two devices. One was supposed to incapacitate ghosts with a high frequency sound, the other was supposed to absorb ecto-energy, rendering a ghost a powerless husk. The former unleashed a sound that was painful to everyone in town, but ghosts. The latter unleashed an energy field that disabled electrical energy, causing a blackout across town.
It's inverted later on when these devices are used in an attack on the Guys in White base in order to rescue Danielle.
RWBY Reckoning shows Darrel's "landing strategy" to be this. In a nutshell, he accidentally ties himself to a tree several meters above the ground. He manages to free himself by cutting his bonds, but as Gravity Is a Harsh Mistress, he ends up falling into branches, and getting nailed in the gonads in the process. Finally, he gets tangled in vines, and is freed by a conveniently timed Blake and Yang. A few moments later, he gets knocked unconscious by his own weapons.
My Immortal has so many examples of Epic Fail that it can not be counted. There is just so much wrong here - the spelling and grammatical errors, the author's complete inability to form a functional plot, the Out of Character Moments vastly outnumbering the in character moments, the obsession with goth/emo culture that the author doesn't really understand. One of the very best examples comes when the author, Tara, writes an Author's Note in response to reviewers calling main character Ebony a Mary Sue and her attempt at a comeback ended... well:
"AN: I sed stup flamming ok ebony's name is ENOBY nut mary su OK!"