Times where someone attempts to Make Wrong What Once Went Right in Western Animation.
- In one episode of Aladdin: The Series, Abis Maul goes back in time to help his own ancestor found Agrabah and in turn become Sultan rather than Jasmine's family. Ironically, this seems to have helped ensure the actual timeline came to pass, since it was a vision of Agrabah that convinced the caravan leader to settle down and build the city.
- In an episode of American Dad! Steve and Snot's high school bully steals a time machine from them in the future to go back and give them advice on becoming popular so they peak in high school and aren't as successful in the future. Their future selves start to notice changes in their pasts and go back to warn them, averting this.
- The Big Bad of Ben 10: Omniverse, Maltruant, sought to remake the universe in his image by going back in time to the Big Bang and sabotaging the Sufficiently Advanced Aliens that created it, only to be defeated by Ben.
- Before that, Vilgax used a Chronosapien Time Bomb to erase all timelines where Ben obtained the Omnitrix, forcing No-Watch Ben to Set Right What Once Went Wrong with Time Master Professor Paradox's help.
- Butch Hartman's first two cartoons each have a movie whose plot centers on this; both play with the trope in the same way, so that they could more accurately be called Make Wrong What Was Once Set Right:
- In The Fairly OddParents!: Channel Chasers, Vicky has become an Evil Overlord in the future and, after stopping Chester and A.J. from going back in time to Set Right What Once Went Wrong, sends a henchman back in time to make sure her future still happens (fortunately, said henchman is actually The Mole who still intends to Set Right What Once Went Wrong).
- In Danny Phantom: The Ultimate Enemy, Danny and co. time travel to the future where Danny has turned evil. His evil future self traps Danny in the future, then goes back in time to make sure his future still happens. (Danny's able to return and stop him with the help of a Deus ex Machina courtesy of a Time Master.)
- One episode of Invader Zim has Zim attempt this trope, tossing little squishy pig toys through a time portal to disrupt the life of his arch-nemesis Dib, who has always thwarted Zim's plans to Take Over the World. Initially, it goes well for Zim, with each pig attack leaving the present-day Dib increasingly crippled and maimed due to the pigs causing horrible accidents for him as a child. Then it backfires when Zim causes an incident that would have killed Dib... except that Zim forgot that Dib's father is a very competent Mad Scientist (if a mediocre parental figure). As a result, Dib becomes encased in a heavily armed life-supporting battlesuit, which he uses to start tearing his way into Zim's lair. Zim attempts to repeat his earlier successes, but instead he just makes the battlesuit increasingly heavily armed, and his ultimately forced to stop himself from ever trying the scheme in the first place. Which causes him to accidentally displace his own brain with a rubber pig.
- In the Kim Possible special A Sitch in Time, the main villains try to use time-travel to prevent Kim from becoming a hero, first by undermining her self-confidence during her early childhood years, then just trying to kill her as a preteen. Shego accomplishes this by sending Ron's family to Norway, effectively breaking up Team Possible.
- This is the plot for the season 5 finale of My Little Pony: Friendship Is Magic: Starlight Glimmer, the insane "Equalist" defeated in the season premiere, decides to get revenge by traveling back in time and preventing any of the Mane Six from getting their Cutie Marks, thus preventing them from becoming the Elements of Harmony and thwarting her plans to create equality by removing Cutie Marks from ponies everywhere. This turns out to be a bad idea when it turns out that the Mane Six are incredibly integral to the history of Equestria that Twilight has to drag her butt through a time portal to show her what her actions are doing.
- Penn Zero: Part-Time Hero: In "Back to the Past of Future Balls", Rippen used a Time Machine to create a timeline where he accomplished his evil goal in "Balls!" After Penn's first attempt to restore the original timeline fails, he tries to go five minutes back in time but overshoots and goes back to the day the feud between the balls (Penn's side) and the racquets (Rippen's side) started and changes history to create a timeline where both sides keep a peaceful co-existence.
- In The Raccoons episode "Time Trap!", Cyril Sneer gets a time machine. Cue the Continuity Cavalcade as he travels back to past episodes and, knowing how his schemes failed the first time, manages to own just about everything. It's All Just a Dream, though.
- A recurring skit on one episode of Robot Chicken featured a time traveler causing all sorts of chaos across history, aptly titled "Dicks with Time Machines." Until he ends World War II by publicly humiliating
Adolf Hitler, whereupon the skit is instead titled "Heroes with Time Machines."- Oddly enough, this was in keeping with Hitler's Time Travel Exemption Act, since Hitler wasn't killed, just humiliated.
- Super Friends:
- In the Challenge of the Super Friends episode "Secret Origins of the Superfriends", the Legion of Doom interferes with the origins of Superman, Wonder Woman, and Hal Jordan to erase them from existence. The rest of the Super Friends find out about this even though they don't remember the three because the Legion's records of them remained unchanged, allowing them to go back and save them.
- In "Return of the Phantoms", after an innocent and ignorant alien rescues three Kryptonian criminals from the Phantom Zone, they steal his time machine and go back to try to kill Superman back when he was the weaker and less experienced Superboy. The alien finds Superman and Green Lantern and sends them back as well to stop them. When the two heroes help Superboy fend off the three, they attempt to blow up Smallville itself out of spite before being taken down.
- In Transformers: Beast Wars, Megatron's ultimate goal is revealed to be this trope, as he used Transwarp energy to travel to prehistoric earth to assure that the Predacon's ancestors, the Decepticons, win the war against the Autobots. In the final part of the three-parter The Agenda, it all leads to Megatron unleashing a full-powered blast at Optimus Prime's head.
- Tarantulus also has this reason for following Megatron. He wanted to kill all the Autobots and Decepticons aboard the Ark. This would wipe out their descendants, the Maximals and the Predacons, but since Tarantulus has a different origin, he'd be fine. He is killed before his plan comes close to fruition though.
- Megatron also tried to exterminate the ancestors of humanity, since humans helped the Autobots defeat the Decepticons. He actually tested whether or not he was stuck in a Stable Time Loop by blowing up a mountain. When the image of the mountain on the Golden Disk changed appropriately, Megatron realized that the future wasn't set in stone. Fortunately, Dinobot shattered the Golden Disk to prevent Megatron from freely manipulating Earth's history though a big enough fragment still revealed the location of the Ark.
- Young Justice (2010): In Seasons 4, Lor-Zod travels from the future of the Legion of Superheroes to kill Superboy in the present, thus preventing him from becoming the main inspiriation for the Legion to form. This is because a thousand years in the future his father, General Zod, attempted to take over the galaxy but was stopped by the Legion and reimprisoned in the Phantom Zone. Three members of the Legion (Saturn Girl, Chameleon Boy, and Phantom Girl) managed to chase Lor Zod into the present to try and stop him. He succeeded in killing Superboy at the end of the first story arc on Mars, while also destroying the Legionnaires' time sphere, thus stranding them in the present. Still not satisfied, he now plans to free his parents and the other criminals from the Phantom Zone a thousand years early by stealing the Phantom Zone Projector from the New God Metron.
