- Chirault: The mages wanted to find a way to expand their living space without breaking peace with tree spirits. They created a Reality Changing Miniature of their whole planet instead. Accidentally.
- Homestuck: Vriska decided to, though Stable Time Loops and manipul8ion, become responsible for creating all the misfortunes currently besetting the protagonists, most notably setting up a multi-million-year-long Stable Time Loop to create a Physical God whose powers would later be transferred to the Omnicidal Maniac Big Bad beseiging her and her friends at the time she executed her manipulation plan. All so she could defeat the Big Bad herself and bail out her "ungr8ful" friends from this mess. It worked...aside from the 'bail her friends out' part.
- Andrew Hussie, the author, knew Act 5's EoA flash [S] Cascade. would be very popular, so decided that he'd best go and look for an outside host. He chose Newgrounds, a site well-known for being able to handle freaking huge numbers of persons. And then, upon release, his fanbase crashed the site. Then Hussie proceeded to crash several of Megaupload's servers when he offered it up for download after Newgrounds failed. There's a reason it's called the post that broke the Internet.
- When Meenah saw that Rufioh (who was dating Damara at the time) was showing interest in Horuss, she tried to pester and mock Damara about it until she snapped and got angry. She did... at not only Rufioh (who she crippled) and Horuss (who she killed), but Meenah as well, killing her in the ensuing fury.
- The Order of the Stick:
- Redcloak transforming Xykon into a lich in Start of Darkness went perfectly, as it allowed them to escape a trap set by a druid who had developed a magic-nullifying disease (undead are immune to disease). Of course, it also added the powers of lichdom to the already Chaotic Evil Xykon, in addition to making him smarter, thus changing him from Redcloak's more-or-less equal partner into a Big Bad determined to prove how much Eviler Than Thou he could be. Xykon proceeded to take over Redcloak's agenda and rule him with an iron fist, to the point where Redcloak is now forced to gamble everything on the completion of his Plan before Xykon grows too strong/impatient/finds out what he's really planning. It is, however, later stated that Redcloak is actually feigning it all, is subtly manipulating Xykon, and views Xykon as nothing more than a useful tool that he only pretends to kowtow to so that Xykon doesn't get suspicious.
- After Haley kills Crystal, her rival in the Thieves' Guild, the guild leader Bozzok spends a pretty penny turning Crystal's corpse into a flesh golem that retains Crystal's memories, skills, and personality, without Crystal's lack of intelligence or focus. In Bozzok's own words, she's now the perfect killer. When he sends her after Haley, she manages to convince Crystal that Bozzok's responsible for her current state, and she turns on him. Even her greater intelligence is a part of this going wrong for him, as she realizes Haley "just" killed her, while Bozzok made it so that she Came Back Wrong in constant, horrific pain, which was arguably worse.
- Yet Another Fantasy Gamer Comic: Gruumsh, the chief Orc god, sought to create a warrior who combined the best of humanity and orcs to unite both people under his banner and conquer the world. When several attempts turned out to be "flawed" in one way or another (one of them being Glon), he intervened directly, removing all the traits he could that wouldn't result in The Ultimate Warrior. The end result of this was Jone, a nigh-unstoppable Stringy-Haired Ghost Girl warrior. Unfortunately, in removing the non-"killing machine" bits from Jone, he seemed to have removed the off switch for her Berserker Rage, resulting in her slaying friend and foe alike and going after Grummsh himself, when he manifested to try and take control of Jone's rampage. We find out later down the line that Glon has a similar berserker inside of him, but his is far harder to bring out and far easier to stop.
- Sluggy Freelance:
Dr. Kirko: You wanted her unstoppable. We made her unstoppable. And now you expect us to stop her?
- Hereti-Corps alien killing machine creation project:
- Though it's a long-standing mystery how she was created and just what she is, and usually she's quite useful, Kusari can apparently slip into this territory. She seems to have been created as a perfect One-Woman Army that obeys the CEO of the evil corporation Hereti-Corp absolutely. Where this can backfire is when someone manages to become the new CEO through Loophole Abuse and sics her on the old one. Such technicalities would hardly otherwise be so significant in a company that's secretly acting outside the law all the time, but Kusari makes them so.
- In Dominic Deegan, the elf-tyrant Raf MaLiksh orders his mages to create an Acibek—a golem of Pure Law, whose power would help end the chaos of rebellion and uprisings he's struggling with. Acibek is lawful, all right, but he immediately realizes that the chaos is due to the tyrannical nature of Raf's leadership, and acts accordingly.
- In Peter Is the Wolf, Butch comes up with a GREAT plan to get Peter! At present? Well, see this trope...
- The main cast of FreakAngels wanted to do something so impressive with their powers that the government would get scared and back off. The story is set a few years after they succeeded.
- The evil Syndicate in Weapon Brown set out to create the ultimate killer with Project Noodle. They succeeded so well that they've kept the only survivor in cold storage ever since rather than risk having him roaming around.
- The major plot element of the first arc of Teh Gladiators, a World of Warcraft webcomic, is the fact that, to increase the popularity of the Arenas, the leaders of the Horde and Alliance arranged for a team of losers and idiots (the eponymous heroes) to win the Arena season by casting a Scroll of Unconditional Victory on them. This plan backfires horribly when two of the team members, Mad Scientist Murlocs Sharon and Yolanda, create a Frankenstinian monster named Cyclonator X32A, which runs wild and wrecks most of Azeroth. Buffed by the scroll, it's unstoppable until Teh Glads manage to lose a match, which breaks the enchantment.
- Schlock Mercenary:
- The Dark Matter entities gave what they said was the plans to turn the galactic core into an engine to the F'Sherl-Ganni so that their respective galaxies wouldn't eventually collide. But many extra Dark Matter entities present at the activation of the drive made it give birth to a new universe that would expand and destroy the galaxy. This was intentional on the part of the Dark Matter entities. But then the plan failed and the core reactor was taken over by Petey, who promptly sent word (and lots of kinetic and photonic energy) back that we had finally noticed we were at war.
- Then there's Dr. B explaining how Project Laz'R'Us synergizes dozens of soldier boosts:Bunnigus: They found that the right combination of these technologies would make any human functionally immortal.
Breya: Okay, but what were the side effects?
Bunnigus: You mean besides turning the entire population into a standing army of Super Soldiers? No side effects. Clean as a razor sharp, double-edged sword-whistle.
- One of the city guards in Goblins torments a captive owlbear in order to turn it into a more brutal killing machine. When he lets it loose on the goblins, he finds out first-hand just how savage it is.
- In Bob and George, Wily created Bass to be superior to Megaman (who, in this comic's universe, is an all-powerfull idiot) in everything. He succeded: Bass is faster, stronger and an even bigger idiot.
- Brian averts/defies this trope in Our Little Adventure. His plan was to demonize and discredit an old magic teacher of his that he tried and failed to recruit to his side. When Brian's part of the plan succeeded better than he imagined it would, he called off the rest of the attack. Brian was worried other attacks would threaten the credibility that one person alone would be able to do them.
- In Commander Kitty, long-suffering #2 Mittens ends up finding his confidence with the help of a spiffy new outfit. Before long, however, the rest of the cast starts to get worried that he's going to overshadow all of them.
- Crankrats: Creating a bunch of walking electrical storms for the express purpose of exterminating your enemies is revealed to be a bad idea.
- Saturday Morning Breakfast Cereal: What happens if you make a robot smarter than yourself.
- In Something*Positive, after Sanderson loses a bet and has to produce a play from a director he despises, he orders Davan to write a script that the director will hate. Davan reminds Sanderson how good he is at that.
- In this strip of Another Videogame Webcomic, Player One, sick of all the attention and coverage NFL player Tim Tebow is getting, petitions to put Tebow on the cover of Madden 2013 in the hopes of passing the Madden Curse onto him. It works and Tebow suffers a season ending injury, but unfortunately, because Tebow is such a media darling, it results in the sportscasters suspending all football coverage entirely in favor of non-stop reports on Tim Tebow's road to recovery.
- The whole strip is basically mad scientists watching their experiments Go Horribly Right, whether it's Helen's Ur-Gerbils or Madblood's robot duplicates. Indeed the main through story is Helen's ongoing experiment on Dave as a potential mad scientist, which shows every sign of having gone Horribly Right when he finally figures it out, goes mad as a result, and seeks revenge.
- Artie comments on this trope in a side story:"Before you ask for an unstoppable killing machine, make sure you really want an unstoppable killing machine."
Gone Horribly Right / Webcomics