Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Bounce a graviton particle beam off the main deflector dish That's the way we do things lad, we're making shit up as we wish; The Klingons and the Romulans, they pose no threat to us— 'Cause if we find we're in a bind, we're totally screwed, but nevermind We'll pull something out of our behinds! we just make some shit up.
Lupin III tends to use Unspoken Plan Guarantees combined with the characters' established skills instead of Ass Pulls, but Lupin discusses this trope at one point when he and his gang of merry men get surrounded.
Fujiko: "I don't suppose you've got a backup Backup Plan."
Lupin: "Yeah, just turn around while I pull it out of the usual place!"
In the Pokémon anime, the "Thunder Armour" seen during the Advance Generation makes all the others look puny. Essentially granting the user(s) invincibility out of nowhere, without being used again at all in the rest of the series? What makes you scratch your head, though, is how Ash came up with the idea in the first place. More importantly, how does his Swellow not get harmed at all?
The show in general is prone to this, especially back in season 1.
Pokémon Special had Ruby reveal out of the blue at the end of his arc that he's had Celebi on hand the entire time. Careful digging through the dialogue earlier on can find tiny hints that lead to it, but it still largely feels this way.
Bleach: Fans tend to call this "Plotkai". Provided it's actually true and not a lie he made up to mess with Ichigo, Aizen's claims toward having been manipulating Ichigo's entire life might qualify. Other examples include Yammy being the Zeroth Espada, Hitsugaya's bleeding and talking ice clone during his fight with Harribel, Ulquiorra having a second resurreccion (which goes against the basic concept of resurreccions), Ichigo's ultimate defeat of Ulquiorra, Sasakibe knowing how to use Bankai (which was only stated posthumously and long after he was effortlessly beaten by a bare-handed Ichigo), and one Sternritter having an identical twin appear out of nowhere.
The last episode of the Slayers anime's first season has this in the form of the Bless Blade, a weapon that is neither seen or heard of until the exact moment that it is needed and whose power rivals that of the Sword of Light and is the only thing capable of hurting the Clone Rezo.
The Gaara vs. Lee fight; Gaara managed to get away from Lee's Initial Lotus by creating a stupidly perfect sand replica of himself, pulling a Replacement Jutsu with it, and burying himself in the ground A.) while rather high in midair, B.) while he was getting the crap beat out of him, C.) in the time it took the person hitting him to blink.
The Great Snake Escape. Following Sasuke's fight with Deidara, Deidara used a gigantic self-destruction technique. Sasuke survived the resulting city-sized explosion by summoning and mind-controlling a massive snake to shield him, when he was explicitly described as being nearly out of chakra just a few panels before. Any one of those techniques would have required a vast amount of chakra, never mind both. Sasuke managed to do all this in the time it took for the explosion to reach him. After it had already started. Just a few feet from him.
Sasuke's teammates developing healing abilities out of nowhere when his life is in direct danger.
The author is lampshading this practice when it comes to Sasuke's new moves. In his fight with Danzo, Sasuke summons a giant eagle out of nowhere. Even know-it-all Madara is left wondering when he had time to acquire the summoning contract.
The Hokage's three guardsnote the third one is a walking version of thisknowing Flying Thunder God. Minato's guards that were never stated to be his guards before, knowing (poorly) how to use an ability he never taught anyone else. Also, only two of these guards were actually previously named characters.
This seems to be the Sharingan's signature ability, pulling out completely new, plot-changing abilities out of nowhere when an Uchiha is in a bind, with no rhyme or reason to them beyond all of them being named after Shintoist deities.
Izanami seems to be the ultimate version of this, with it being only useful against Izanagi users and Kabuto or those like him, whom the user happened to be fighting at that moment.
Chapter 618 contains several fairly gratuitous examples of this - Tobi apparently placed six Zetsu clones within Sasuke to spy on him, which can be drawn out by Jugo's abilities, and there happens to be more than enough of them to act as sacrifices for the jutsu that Sasuke's group was going to use. The only reason that the group knows about this was because Orochimaru read Kabuto's mind somehow. There's an Uzumaki shrine on the outskirts of Konoha that hasn't been mentioned before (and, since Naruto is one of them, you'd think it would have come up) which contains a mask that gives its wearer control over the god of death. This, combined with the six Zetsu clones, allows Orochimaru to revive the four Hokages in spite of the fact that they were stated to be impossible to revive, as well as giving him a new body to transfer to and allowing him to regain the use of his arms. A fairly awesome moment, but that doesn't change the fact that none of this had been built up to beforehand.
Chapter 632 has Sakura using Tsunade's Yin Seal to make it so that she can fight on the same level as characters like Naruto - the fact that she used it was not necessarily an ass pull, since she trained under Tsunade over the course of the time-skip, but it's claimed that this technique required her to store up chakra for three years in a half-hearted attempt to justify Sakura's poor performance over the course of the post-time-skip period when the fact that she'd been storing chakra for all that time was never mentioned or hinted at previously. Hilariously, for all that Sakura goes on to accomplish very little, even with the Yin Seal.
Chapter 648: Sasuke suddenly has the ability to combine the curse seal that Orochimaru originally gave him (which he doesn't have anymore) with his Susanoo.
The cliffhanger in which Maria is locked up in a train car with a time bomb ticking down. In the next episode, she is saved from the wreckage by Yunyun. It's unclear how any of that happened and how Maria managed to survive her gunshot wound afterward, even though Yunyun had been carrying her around for hours.
Alphard surviving her fall of several meters also has some of this. Sure, the woman is strong, but that is just ridiculous.
Ral & Grad: The very final battle ends with Ral exploiting a quality of Shadows that was never mentioned before, contradicts almost all of what we were previously told, requires several Wall of Text word balloons to explain, and apparently exists solely to facilitate a Bittersweet Ending.
In Blassreiter's Final Battle, a fatally wounded Joseph finds himself in a strange pocket dimension with the spirits of Gerd and Hermann, who take over his body to fend off Xargin until he bounces back. May be an unexplained Amalgam ability, as Elea uses this later for the series' Crowning Moment of Heartwarming.
A character example in Deadman Wonderland. Despite how long Toto Sakigami, who had previously mysteriously disappeared before the series began, sticks around before the other characters figure out he's another one of Hagire Rinichiro'sGrand Theft Me victims, it isn't until Chapter 42 that we meet the first significant character from the original Toto's backstory: his Morality Pet, Mitsuzaki Yosuga. They were apparently so close that she outright stated she was in love with him, and they had more or less adopted each other as surrogate siblings. Okay, fair enough, even someone as universally feared as Mockingbird can have friends; though, this does beg the question, if she cared about him that much, where was she when Mockingbird first returned more than twenty chapters ago, had a party thrown especially for him which appeared to have been attended by every Deadman except her, publicly annihilated no less than three Forgeries on the first ever open-to-the-public Carnival Corpse which was streamed on the internet, and then strutted about G Block like he owned the place for several chapters after? You'd think she'd have been all over her 'onii-chan' reappearing all of a sudden, but nope, she doesn't make a single appearance, not even as a Chekhov's Gunman, until the Return to DW arc. Talk about a gaping Plot Hole.
Yami No Matsuei does this a lot in quite a few of its murder "mysteries." The worst offender is quite possibly the King of Swords arc. Oh no, the evil doctor Muraki has been killed! Who could possibly be the culprit of all the continuing murders then? Why, it's actually Tsubaki, who had actually been taking a never-before-mentioned, fantasy drug that made her develop a split personality. And Muraki isn't actually dead - all along, he actually had the ability to survive deadly poisons from taking poison since an early age, which was also never mentioned before! So in the end, he still was the culprit. Why didn't anyone think of this? It should've been so obvious.
The first Digimon Adventure 02 movie (the one that was remade to make up the 3rd part of the movie released over at the states). Kokomon has evolved to Cherubimon, a powerful Mega digimon that's essentially invincible, and this is during a time when only one of the characters can have their Digimon reach Ultimate, which is just one stage below. So, what happens? Out of freakin nowhere, Angemon and Angewomon evolve to their never before seen Mega levels, Seraphimon and Magnadramon, despite everything in the series' canon going against this. However, it gets worse. Do the two holy Mega-levels destroy Cherubimon? No. Instead, they use their energies to summon two Armor Digieggs to evolve Terriermon and Veemon, one of which had been used up in the main series, to Armor level. It isn't explained why they can do that, either. Sure, it's a Non-Serial Movie, but absolutely none of this was explained very adequately in the movie itself, which hadn't been half-bad until this happened.
Speaking of which, the Christmas episode's twist — Sora and Matt's sudden dating — was viewed by some in this light.
As was the revelation of MaloMyotismon as the final Big Bad, considering he'd died twice the previous season, he became part of another villain who was subsequently killed and he was killed a fourth time during an in-canon game.
Another 02 example: the explanation of why the older DigiDestined can no longer digivolve to Ultimate or Mega. Essentially, they gave up their crests (which were already destroyed) to create a barrier to protect the Digital World (which neither worked nor was ever shown or brought up again). The writers caught on that this was a pretty silly plot point and changed the reason why they gave up their crests: they had to awaken the Digital World's gods (the Sovereigns). This too is an Ass Pull because 1) the Sovereigns were almost immediately resealed and 2) the only things the Sovereigns (actually, just Azulongmon, we never see the others) actually do is fix the Destiny Stones (which would not have broken if their digimon could go Mega at will again) and give the older Digimon the ability to reach Ultimate and Mega again (which, again, wouldn't have been a problem if they had their crests).
The duel with Dartz, where Dartz has managed to summon a monster with infinite attack power. Yugi's counter? Infinite feedback loop of two monsters powering each other up ad infinitum until THEY have infinite attack power, too.
The first time Yugi played Capsule Monsters with Mokuba in the manga. How did Yugi know that the random monster he put off to the side could use that one move that would finish off all of Mokuba's monsters in one turn? How were we supposed to know that it even had that move to begin with?
Most of the episodes tend to come down to this. Dan Green refers to it as the "Pull-it-out-of-my-butt card".
Yuki Judai, The Hero from Yu-Gi-Oh! GX, is a very prominent example. His E-Hero deck revolves around combining the monsters of said archetype via the Polymerization card. As you can imagine, this results in Judai pulling a never before mentioned fusion monster out of nowhere every time he’s in a pinch. The trend continues with the Neo Spacians and E-Hero Neos; to the point he even gets to fuse the latter with other people’s monsters. And that’s without mentioning the loads and loads of situational spell and trap cards, which are normally so specific for a certain situation, that including them in one's deck would normally be foolish. One of the worst offenders is Jun Manjoume's card, "Ojama Ride", which discards "Ojama" monsters to special summon Machine-type "Union" monsters. "Ojama" and "Union" monsters have nothing in common, so this card would probably be useless to anyone except Manjoume, whose Deck happens to use both types of monsters.
The Zexal Weapons in Yu-Gi-Oh! ZEXAL can be seen as this, as they get Yuma Tsukumo out of whatever jam he's in. Justified as the cards themselves don't actually exist until Yuma and Astral create them through Shining Draw or Dark Draw.
One Piece fell victim to it in the anime's Ice Hunter filler arc. The Big Bad has the ability to generate and control absurd amounts of heat, which allows him to take casual lava baths and by manipulating the heat in that lava, create lava tsunamis. Due to this immense heat Luffy couldn't touch him without getting severely burned, which, given Luffy's fighting style makes him unstoppable. In the final moments of the fight the big bad tries to ram right into Luffy, who grabs him with his bare hands, shouts a few times, and throws him across the battlefield, ultimately suffering a few minor burns from the ordeal.
In the actual manga we have Pell surviving Crocodile's bomb, and Blackbeard being capable of using two Devil Fruits, not only in and of itself, but because it was stated Blackbeard can only do it because he happens to have a special kind of body.
Blackbeard's little trick was foreshadowed a bit, but it doesn't really do anything to lessen the applicability.
Blackbeard (In Impel Down): We'll put on a show that'll shake this world to its core!
In the 4kids dub, immediately after Luffy refuses to take Robin's Eternal Pose to Alabastanote originally it was to Naninomai Island, Vivi speaks up and says she happens to have one, enabling them to bypass the Little Garden arc, making the entire decision pointless.
Many find the end of the Soul Eater anime to be this. The Kishin Asura was wounded by Maka because, while unconscious, she attacked Asura with her newly-awakened weapon powers until Asura caught on and forced her back into consciousness. To top it off, one minute later, she uses one punch and kills the Kishin in one hit.
Natsu's fight against Totomaru. Totomaru can control any flames around him so anytime Natsu tries to use one of his fire attacks, it gets deflected or reversed against him. Completely out of the blue (two pages before, Natsu was still getting his fire deflected), Natsu suddendly learns how to negate Totomaru's control over his flames. There isn't even an explanation on how he managed to do it.
A better example would be the ex-balls, which grant people the ability to use magic while in Edolas. Not only are they first mentioned when it's absolutely necessary that Natsu and Wendy get them, but Lucy conveniently forgot that she'd been given one already.
The Tenrou Island arc introduced us to Zancrow, a Hellfire Godslayer dark mage who starts kicking Natsu's ass. There is no way for Natsu to beat him, as he can't eat Zancrow's fire, so he shuts his own magic off, and that makes him able to eat the hellfire with no problem at all, and beat Zancrow in two seconds. And no one told him how to do it. Even the narrator within the anime stated "Somehow, Natsu defeated God Slayer Zancrow".
In the same arc, Natsu absorbing Laxus's Thunder Dragon power, and before that, Laxus being able to match an opponent that curb-stomped Makarov.
Also in the same arc is Erza's victory over Azuma. The latter uses his strongest attack, Terra Clamare, which blows up all the magic in the island in her face, seemingly defeating her. At that point, Jellal, miles away in an Anti-Magic jail cell, somehow realizes that Erza is in a losing battle and somehow Erza is able to hear his words of encouragement, getting her back into the fight. Eventually Azuma uses Terra Clamare again... but instead of inflicting massive damage like before, the attack is converted into The Power of Friendship and allows Erza to beat the much less injured Azuma in one strike.
In a similar vein to the above, Natsu eating Etherion is one of the best examples of Ass Pull/Deus ex Machina in the series.
Erza's victory in the Grand Magic Games. She goes up against Kagura and Minerva at the same time before Minerva leaves the two to fight each other. Erza is actually getting curb-stomped by Kagura, and when she takes the blame for the death of Simon, Kagura's brother, Kagura unsheathes her sword Archenemy with enough force to destroy much of the city.. but Erza easily blocks the sword with her own and turns the fight around. When a flashback shows that Erza and Kagura were from the same village and the former saved the latter from slavery, Kagura becomes unable to continue fighting, giving Minerva the opportunity to stab her from behind. Minerva proceeds to further beat up Erza until she whips out a never-before-seen armor described in story as basically screwing the laws of magic, and one-shots Minerva. Again, Minerva was barely injured while Erza was not only covered in blood from head to toe but also had a shattered foot.
In the second season of Zero no Tsukaima, we see the atoning professor Jean Colbert die in a fight, and Saito and Louise holding each other while mourning his death - a touching scene for many a fan. Then in the third season, lo and behold, he lives! Turns out one of the witches of the academy cast a fake death spell on him for no apparent valid reason. At least part of the spoiler is less absurd than the rest; the spell in question was cast using water magic by a fairly high-level mage adept in its use. Water magic in this series is associated with healing and grants a degree of control over the body, as demonstrated early in the second season with the Ring of Andvari and Zombie Wales. The execution still leaves something to be desired, though.
Despite their importance later on, Newtypes are this in Mobile Suit Gundam. They aren't mentioned, or even hinted at, until more than halfway through the series.
In the latter half of Mobile Suit Gundam ZZ, Leina is supposedly killed by a falling Mobile Suit. She inexplicably returns near the end of the series, having been rescued by Sayla Mass from the original Gundam series. How this is possible is never actually explained, with Sayla's cameo being Fanservice more than anything.
Heartcatch Pretty Cure's movie had one with the Miracle Lights. While most of the other Pretty Cure movies had these minor MacGuffin show up either in movie or during the movie's introduction, their appearance here is extremely jarring, especially since, by that time, they had the Heartcatch Mirage item, thus no real need to need it. It's also jarring because the series was much more down to Earth than its predecessors or successors.
Though Rebuild of Evangelion did a good job distracting the viewers from noticing/caring about it, the big scene at the end of Rebuild 2.22, where Shinji defeats Zeruel NOT by going berserk, as what happened in the original tv series, but rather, through a new process that hasn't yet been identified, demonstrates several new abilities in the EVAs never before hinted at.
Think of an ass pull as a giant, snowcapped mountain for a second. Gurren Lagann took a sled and rode that mountain from start to finish. Fortunately, the series runs on Rule of Cool and can abuse this however the hell it wants. There's a reason it's the Trope Namer for Beyond the Impossible: Internal logic is nothing more than a friendly suggestion.
The Attack on Titan manga has Eren turn out to be the 'coordinator', a shifter capable of unconsciously commanding titans. Not only does this happen when survival is otherwise out of the question, it shows up a long way into the series, with foreshadowing only appearing a few chapters beforehand, and Reiner and Bertolt suddenly having been completely aware if its existence. Not the worst example of an ass pull, but it was quite jarring coming from a series which was otherwise well thought out with meticulous detail.
Shigure Kosaka from Kenichi: The Mightiest Disciple uses actual telekinesis as her ultimate technique, though limited to control her opponents weaponry. The series has never even hinted that supernatural abilities of the sort are possible, and being a long runner where everything is somewhat rooted in reality, it's ridiculous to see it now.
The biggest complaint about Puella Magi Madoka Magica The Movie Rebellion is that Homura's soul gem being corrupted by love not only contradicts the established rules of the series soul gems are corrupted by usage of magic and via despair, but came with absolutely no foreshadowing.
Dragon Ball Z and the whole "Namek blows up in five minutes" thing was later revealed in other material to be an Ass Pull on Frieza's part. His attack was meant to be an out-and-out Planet Killer, but panicked as he feared that the explosion would be too much for him to survive and held back. Caught with egg on his face, Frieza threw out the five minutes number to save face.
Douwe Dabbert has a magical knapsack which provides him with everything he needs in cases of emergency.
Dilbert describes this trope as the source of his company's documented process:
... and our documented process was pulled out of someone's lower torso.
ElfQuest has a famous one in its main canon: when Blue Mountain collapses, all of the Gliders die, and for... some never explained reason, their spirits can't find the afterlife yet. Rayek, whose powers were previously canonically limited to hypnosis and lifting things, absorbs the spirits into his own body and decides to go on a quest to accompany them to the Palace (where elf spirits generally go when they die). Clearbrook and Treestump decide to accompany him on his quest... although even they don't seem to be quite sure why.
The Justice League of America once went up against Despero (an alien with vast mental powers, at the time recently powered-up to be almost as strong and invulnerable as Superman) with a mostly C-List team. How to beat him? With an innate Martian power that the Martian Manhunter had never before mentioned that he had, because using it was so stressful that any given Martian can only do it once in their life. Despite that, it was still a fairly well-received story. Another weird power of his was the ability to see through the flow of time. This somehow resulted in him being immune to the powers of an opponent who completely rewrote reality. Pulling never before seen powers out of his ass is the Martian Manhunter's shtick. And then getting lit on fire the next time said power would have been useful.
Deathstroke's victory over a Justice League of America team in Identity Crisis can only be described as a complete and total Ass Pull. Sure, the team of heroes he fought didn't include Batman, Superman, or Wonder Woman (two of whom would barely notice Deathstroke if he attacked them, and the third, Batman, would be ready for him if he did), but it did include the Flash and Green Lantern, neither of whom was portrayed as actually knowing how their own frigging powers worked during the fight. It was, in fact, embarrassing. For the writer.
Appears a lot throughout the Silent Hill comics written by Scott Ciencin. Way too many to list as the situations that called for the sphincter-tugging is due to Voodoo Sharks put in by the author everywhere in the comics, but one fact bears mentioning: Lauren getting the magic book she needed to fight the whole story's Big Bad, which is coincidentally made out of something he is specifically weak to, by buying it from E-bay.
The Clone Saga from Spider-Man, where back in 1975, an exact clone of Spider-Man appears, and at the end of that one issue, seemingly dies. Except he didn't die, showed up again in an issue some 20 years later, and mentioned that out of absolutely nowhere, that he was the original the whole time and that the Peter Parker the comics had been following for the past two decades was really the clone. Fans were so angry at this revelation that they essentially just said that the clone was lying and was created by the Green Goblin, who died in 1972, but to pull this off, was also actually alive the whole time.
Superman had pure kryptonite injected into his veins, yet was still able to overpower a villain who had been a match for him even when he was healthy.
Silver Age Superman stories were notorious for coming up with convenient new powers for the main character all the time.
In Chapter 8 of Forbiden Fruit The Tempation Of Edward Cullen, Tiaa gets out her previously unmentioned samurai sword (she often has it with her!!!) but never gets a chance to use it. Unfortunately, it can be said without exaggeration this is the very least of the fic's problems.
Soulless Shell: This fic appears to be merely a poorly-written RedwallTransplanted Character Fic until Chapter Three, whereupon we abruptly and without warning come upon the line "then he shot a beam from his paw which the rat teleported away from". (For those unfamiliar, Redwall is a medieval fantasy about talking animals, and has a definite lack of magical laser beams.)
Spartianfox's self-insert character in his Videogame Rescues series has this as a stated power. His great uncle (who introduced him to the series' Multiverse and gave him his supertech portal armband) told him that his powers include "any weapon, item, and powerup from a video game." Effectively, his power is "pull whatever I need right now out of nowhere." The series is still fairly well-written and the author has gone on to write and publish original works.
Can be found in many Deadliest Warrior fanfictions, such as when numbers of kills are provided at the end of a fight. Unless there's a home version of the Slitherine Studios battle simulator available, there's no way the "kills" represent one thousand actual simulated battles (especially if the author admits they chose the winner based on a vote, or just their own personal opinion). Also occurs when a chosen character lacks a weapon that fits into one of the short range/mid range/long range/special weapons categories. The solution? Make something up! The categories MUST be adhered to, even though the actual show was never so strict as to only deal with that set of criteria.
The Locking Ladle of Ranma ½ always seems to conveniently show in fanfiction where its application would prove useful in the storyline, for better or worse, no matter where its current location in canon is. Besides that, there are a million other ways of locking a Jusenkyo curse in fanon by now. Locking rings, water treated by the Locking Ladle which is no longer in it, special potions...
Lightning suddenly being able to summon the Uniforce because he remembers to believe, right when Titan is going to kill him.
Brain turns out to have a spaceship in his backyard, which the others use to escape the exploding Unicornicopia.
Celesto and Celestia fusing and turning into the Great Celestial Ruler, who destroys Titan.
Reality Checks Nyxverse gives us one in Nyx's Family, the infamous Chapter 11, whereas it is revealed that , during the founding of Equestria, Luna and Celestia used a magic mirror to request the advice of several HUMAN economists (all right wing or libertarian economists mind you, no exceptions) in order to create an economic system for Equestria. Up to this point in the narrative there was absolutely no indication that the Alicorns nor any other Equestrians were even aware of the existence of humans, let alone in contact with them, and definitely no reason given why they should value human knowledge or seek out human advice.
In The Evil Gods Part I, Jerry somehow realizes in the middle of his first fight with Percy Jackson that Percy placed a traitor inside his group. A later chapter reveals that God told him there was a traitor the night before Percy attacked, but didn't say who it was.
In The Titans Strike Back'', when the Prayer Warriors' weapons and prayers fail to defeat Lola, Draco prays for God(never mind that Lola had the ability to make that impossible with her wind powers) to turn his sword into a holy vacuum cleaner, which sucks her up and kills her.
In Street Kings, in his darkest hour, Keanu pulls a handcuff key from his ass. OK, it was hidden in a special pocket under a seam in his jeans, but considering that it was never even alluded to earlier, the trope applies.
In The Woods, a truly crazy DTV-horror film. The plot for most of the movie has to do with the discovery of an ancient skull reviving a demon who commits murders that the discoverer gets blamed for. The latter half of the film turns wildly incoherent as plot turns start getting introduced out of nowhere; including a second monster to whom the first is a dog, and a historical setup that depicts ninja swordfights between northern MichiganNative Americans.
John Carpenter himself admits that while writing Halloween II (1981), the idea of Laurie being Michael Myers' sister came to him "at 2:00 in the morning in front of a typewriter with a six pack of beer."
In Live Free Or Die Hard (aka Die Hard 4.0), at one point the only method of transport available to John McClane is a helicopter. While starting the chopper up, McClane, a New York cop who barely ever does anything extracurricular except drink, reveals he 'took some lessons' once and flies himself and companion away. Not even a Chekhov's Skill mentioned before this point. It may have something to do with what happened in Die Hard 2:
Chopper Pilot: [McClane is showing his nervousness while riding in a helicopter] What's the matter, cowboy? Ride too rough?
This was actually done to fix a continuity error from the previous films. In the first two, McClane has a dislike of flying, however he rides in a helicopter near the end of the third film without issue. When fans pointed this out, the writers put this scene in the fourth film to address it.
The Superman movies angered comic book fans with some ass-pulled powers, particularly the ability to turn back time by making the Earth rotate backwards as the Deus ex Machina ending of Superman, and the universally reviled "cellophane S" and memory-wipe kiss from the theatrical Superman II.
The memory-wipe kiss did appear in the comics first, although it was just as much an Ass Pull there, too. Heck, the Silver Age Superman comics were the undisputed champion of Ass Pull superpowers, come to think of it.
Some view the reverse-rotating earth as a botched visual effect - meant to indicate that Superman isn't altering the Earth but instead traveling through time and (from his perspective) the Earth is rotating in reverse.
In the porn/cop film Busty Cops a group of police detectives are trying to discover who the murderer is. After some encounters, the group head back to base and a talking llama tells them who did it...
In Highlander The Source, Duncan suddenly acquires super speed to be in equal match against the Guardian. They never said he could do it or how he was trained to do it, he just does.
The sudden appearance of Frankenstein's Monster and Count Dracula (with his wife) near the end of House Of The Wolf Man come off as this. The Monster's presence isn't that much of a stretch, as a member of the Frankenstein family is the owner of eponymous house, but Dracula? With no foreshadowing whatsoever, he appears in the doorway and is invited in.
Dragonrider is a big offender. One example of the author's lazy style features a character meeting a fellow magical ("fabulous") creature far away from home and well beyond the book's halfway point. Any potential language barrier is then sidestepped as she addresses this creature "in the magical language that all fabulous creatures understand".
Parodied in Douglas Adams' The Hitchhiker's Guide to the Galaxy; in the first book alone, the characters often escape danger in wildly improbable ways such as being unintentionally picked up by the Heart of Gold and avoiding death by missile due to the missiles being transformed into a sperm whale and a bowl of petunias by the Improbability Drive. Many of the other books also contain plot elements that come from out of what can only be described as left field perceived by Hunter S. Thompson, oftentimes accompanied by the book pointing out just how improbable they are. This is much more blatant by Mostly Harmless: Arthur Dent's daughter is named Random, and her behavior, which plays heavily into the conclusion is... well, random.
The Inheritance Cycle features a big 'un in the shape of magical elf twins, never previously mentioned who cure Eragon's achey back scar, allowing him to fight properly again. They turn up once more in the fourth book make it so Dwarfs and Urgals can become Riders as well, thus solving all racism forever.
The Deathly Hallows from Harry Potter and the Deathly Hallows. While the Horcrux plot showed Harry he could stop Voldemort from reviving again and again, it didn't help his chances in fighting the man in person. Cue the Deathly Hallows. Apparently Dumbledore had a complex history involving Grindelwald, his friend-turned-dark wizard, and the Elder Wand, one of the Hallows and an unstoppable weapon whose nature turns the final duel with Voldemort in Harry's favour. The story of the Hallows is a fairy-tale familiar to all wizards, but we don't hear about it until halfway through the last book. Harry's cloak and Marvolo's ring (now a Horcrux) are Hallows as well but impossible to foresee, as is the whole complex history of Dumbledore.
Thankfully, there was at least a limited amount of foreshadowing in the previous books, albeit not enough to predict Deathly Hallows's events; there's Dumbledore having James Potter's cloak, despite the fact he doesn't need one to become invisible, the night he and Lily died, the description of Marvolo's ring and the mystery of why Dumbledore put it on, and passing references to Grindelwald, Aberforth, and Dumbledore's broken nose.
A true example of an ass pull in the last book: Fiendfyre. Harry's faced with a Horcrux and no way to destroy it? Well, guess what? There's a Dark Magic spell (never so much as even implied before) that can destroy Horcruxes, and it's designed such that the dumbest student in Hogwarts can cast (albeit not control) it!
Ron enters the Chamber of Secrets by learning to speak Parseltongue. Only not really because he was just imitating the sound of it. And the Chamber figures "eh, close enough" and lets him in anyway. This is despite Harry, a true Parselmouth, being unable to speak it unless he's convinced he's talking to an actual snake.
In Simon R. Green's Something from the Nightside, Joanna is an Artificial Human sent to trick the main character into entering an evil house. We find this out while the main character is in the house. Joanna fades into the wall and is never seen again. More or less everything in the sixth book comes out of one posterior or another.
The Big Bad vamps Victoria, James, and Laurent were not mentioned at all until the very end of Twilight, thanks to 90% of the book being about how perfect Edward supposedly is. The movie rectifies this mistake and has them shown earlier. The role of the Volturi in enforcing the rules of vampire society was similarly introduced out of the blue in New Moon.
Several in Lonely Werewolf Girl, due to a Random Events Plot. Two especially egregious ones show up during the final battle: Thrix being able to Mind Meld, thus also being able to re-activate Beauty and Delicious' lycanthropic abilities, and Kalix being immune to the mind-affecting power of the Begraver Knife because she's "too crazy".
A Dance with Dragons, the fifth of the superbly written A Song of Ice and Fire series has an apparent one with the revelation of a second surviving Targaryen, Aegon. Series canon often references his broken, bloody baby head. The only indication of Aegon's continued existence before the current book was a difficult-to-understand prophecy in the second book about a cloth dragon used by mummers in their performances(presumably, Varys is the mummer, Aegon is the dragon). Fan forums are usually alive with speculation about Secret Targaryens - and a few correctly predicted the development based on the aforementioned prophecy - but to many dedicated fans, this one came from that place where the sun don't shine.
Considering the inspiration for the series, the possibility of pretenders with spurious evidence, potentially legit claimants that are more distant in blood relation or justification, royal bastards, and so on coming out of the wood works to claim the throne isn't really an ass pull. If anything its a case of Real Life Writes the Plot since its something that used to happen all the time, and a lot of times without warning, in a destabilized country. It still does happen, albeit with a decided lack of royalty involved in most cases.
Ronald Knox's Decalogue was a reaction to the Asspulls pervading the mystery genre. The commandments address the most prevalent of the time, ie: presenting last-minute characters as culprits, inventing Phlebotinum weapons, adding hidden doors that wouldn't plausibly be designed and serve no function other than to obfuscate closed rooms.
In Animorphs #19: The Departure, Cassie makes a deal with a Controller: it will leave its host and go back to life as a helpless Yeerk slug if Cassie traps herself in morph as a helpless caterpillar. Cassie does so, and it seems she's now stuck as an insect for life. But wait! It turns out the caterpillar's metamorphosis into a butterfly reset the morphing clock, allowing Cassie to become human again. Hooray for sudden non-foreshadowed loopholes.
About halfway through The Wise Man's Fear, the protagonist and his team have finally finished a difficult mission fraught with setbacks. On their way back to town...they stumble onto the indescribably beautiful Queen of the Fae, who then seduces the protagonist and carries him off to Fae. His time there takes a full sixty pages.
For an example of the "Character Made It Up On The Spot", in The Original Series' "The Corbomite Maneuver" Kirk pulls some Corbomite out of his ass, calling it a material that can reflect the attackers' destructive potential back on them and everything else in a large area and then some. It was entirely a bluff to get Balok to back down. It worked so well, he pulls it out again for some Romulans in "The Deadly Years".
Notably, Harlan Band tries the exact same maneuver (in a bit of a Shout-Out) against the Spung in an episode of Space Cases. It doesn't work, apparently because the Spung warlord is played by George Takei.
Spock's "internal eyelid" in "Operation - Annihilate!" Never mentioned before. Never mentioned again, right up until a single episode in the final season of Star Trek: Enterprise.
Kirk is clearly the master of this maneuver, as in "A Piece of the Action," he generates the card game Fizzbin from the orifice mentioned in the trope's name, complete with nigh-indescribable rules. Suffice it to say, you don't want two jacks and a king on Tuesdays at night.
Kirk's mastery of this extends as far as confusing people long enough to get a good grip on the table that's going to be upended.
Also in the final season, the reveal that Dana Walsh is a mole. Not only does it come out of nowhere, but suddenly the way she dealt with her criminal ex-boyfriend in the season's first half makes no sense, as with her new characterization she clearly would have just killed him.
Alan Wilson comes out of nowhere and is revealed to be the true mastermind behind Day 7 and Day 5 events.
Dallas: Perhaps the ultimate in television is the infamous reappearance of Bobby Ewing in the shower.
Thank God You're Here is a sketch/game show where various comedians are brought into different sets with different plots and as different characters. They aren't informed as to what they're going to be doing or who they're supposed to be - though costumes can occasionally give them hints- and they are required to play the role they're given as best they can. It's like Whose Line Is It Anyway?, but without the explanations.
The Lost Room: The business about the Law of Conservation of Objects comes out of nowhere in the last five minutes of the series and is crucial to the resolution of the main plot.
Stargate Atlantis needed a "dramatic" way to get Atlantis involved in the battle with the Super-Hive, so Zelenka pulled "ass drive" out of McKay's wormhole.
Every previous season finale ended on a big cliffhanger. It was obvious that the cliffhanger this time was going to be a Wraith ship in orbit of a defenseless earth; but when they found out they were canceled, they had to wrap the plot up in-episode. A little bit of ass pulling seemed like the better alternative...
The whole "moving the control chair to Area 51" bit also seems like an ass pull, simply to put the chair (and the research facility with it) in a position to be blown up before it can be used to fight the Super-Hive. The reason given for moving it doesn't make sense at any possible level, either. The (real-life) treaty banning militarization of Antarctica certainly would not apply to an artifact predating humanity itself, and the IOA (which was founded for the explicit purpose of preventing America from monopolizing alien technology) would never have insisted that the chair be moved to America; as international territory, Antarctica would've been the perfect place for it from their perspective. Not that it would've done much good, given how well Atlantis's own drones do against the enemy ship.
The Doctor managing to disrupt the Daleks' power supply in "The Power of the Daleks".
Classic Doctor Who also has several examples, such as the Doctor's never before mentioned 'respiratory bypass system' which saves him from strangulation in "The Pyramids of Mars".
The Gallifreyan mind meld in "The Girl in the Fireplace." Had there really never been a suitable reason to use it at any time in the previous 27 seasons?
The software patch that makes the bad nanites be good nanites at the end of "The Empty Child."
Then there's Captain Jack Harkness' performance in Bad Wolf. While completely naked he reaches behind himself and produces a small laser gun. This is immediately lampshaded when he is asked where he got it from. While the act in itself is an Ass Shove, it also qualifies as Ass Pull as there was no indication that he had it prior to using it. It was a scene played for laughs though.
It may sound incredible, but the now core concept of regeneration was itself an Ass Pull. William Hartnell was getting too ill to play The Doctor, but they didn't want to end the show - so Hartnell himself came up with the idea that Time Lords could regenerate into a new body.
There was no mention of this before by either sides but in Charmed Season Eight, there seemed to be the Ultimate Power that is more powerful than the Charmed Ones and they are a pair of sisters.
In The New Adventures of Old Christine, Christine's brother Matthew is a nanny for her son Ritchie during Season 1. Then he enters medical school, drops out later that season and then suddenly a therapist seeing patients. He even says that he "glad he's a doctor" now, indicating that he has somehow obtained a Ph.D. in psychology over the course of a semester.
Inverted in the episode "iSpace Out", where Carly is suddenly revealed to be aggressively claustrophobic, and breaks the window of a training space station module to escape, despite multiple occasions earlier where Carly is perfectly normal in spaces that are half that size or less. The inversion is that the Ass Pull isn't used to resolve the plot, but in fact to fail the plot and bring about an end to the episode. This was done because the writers knew that having iCarlyin space would be seen as a jumping-the-shark moment and therefore had to find a way to stop it.
Played straight with Sam liking Freddie in iOMG. It's an Ass Pull because of the desire to create a Shocking Swerve season ending Cliff Hanger ending. In iOMG Sam liking Freddie just happens. There's no previous episode arc or foreshadowing or explanation to the audience that Sam likes Freddie. The focus is on protecting a cliff-hanger ending where Sam only reveals she likes Freddie right at the end of the episode, leaving Freddie's response as the cliffhanger. Having any indication that it's Sam and Freddie would kill the swerve. They also use Brad as a Red Herring. In fact, the characters on the show itself make reference to how suddenly and strange it is, as they only mention that Sam's behaviour only started when Brad showed back up, which was only for that episode. Sam showing signs of liking Freddie before it would kill the plot of the episode and spoil the dramatic ending. Later on in the short arc the reason is revealed to have been an incident that was never shown, took place entirely off screen, with no reference as to when it happened.
What is the Power of Thunder? Never really explained. Where did it come from? Never asked. If its always been available, why not use it sooner? Never brought up. The transition seriously gets a single short exchange of dialogue and is never questioned again.
The "transition" (term used very loosely) between Power Rangers Zeo and Power Rangers Turbo. And before that, the "Sword of Light" needed to transfer powers to another person back in Season 2 of Mighty Morphin'. Never mentioned again, and later power transfers just have the original Ranger giving their power coin/morpher to the new Ranger.
Though this is more of an in-universe example than a proper Ass Pull, Psych employs this when Shawn, desperate for an explanation, claims that a man was killed by a T. Rex. Then it turns out he was a paleontologist and, on dying, fell on a skeleton. Even Shawn is surprised by this.
Shawn claiming to be psychic at all is an Ass Pull on the character's part. He was just trying to get out of trouble and the cops wouldn't believe the real story - that he's just really observant.
Towards the end of Season 2 of Vampire Diaries Bonnie's magic has become this, with her coming up with incredibly convenient spells for numerous bad situations the characters have found themselves in.
It's helped a bit when it turns out that her using such powerful spells has pissed off several witch spirits, who are now very reluctant to help her again.
Also toward the end of season 2, the "twist" that the Sun and Moon Curse was a lie planted by Klaus and Elijah and the real curse was on Klaus, suppressing his (newly announced!) werewolf side.
The fourth season of Sons of Anarchy has a whopper in the season finale. The season spends a good deal of time focusing on an Assistant US Attorney who spends the bulk of the season build a big RICO case against the son that eventually sees two of their members flip (albeit one of them under duress) and one of them go to prison. The aforementioned Attorney and his people are all set to move on a gun deal the Sons are planning and their sure to at least make some arrests. Suddenly, the Cartel guys introduced early in the season drive up, reveal that they are in fact CIA agents and tell them to close down the investigation because the CIA is using the club to take down bigger fish. This plot twist (alongside the Irish's sudden refusal to deal with anybody but Clay) not only crushes the RICO investigation but prevents Jax from killing Clay, Jax from being able to leave Charming, saves Bobby from going to prison, allows Juice's disloyalty to stay a secret from everyone in the club and leaves Jax forced to do the CIA's bidding with the threat of them letting the RICO investigation go through should Jax turn on them.
The metaplot of Legend of the Five Rings RPG's second and third edition may be considered full of Ass Pulls with killing off main NPCs and gods, as the authors simply interpreted the outcomes of official L5R CCG tournaments instead of coming up with something more coherent themselves. Way less than graceful. Made even sadder by the fact they've been doing it with the game's metaplot since day one. Some are great twists, others... not so much.
GURPS has several advantages that let the players do this, including Gizmos, which allows you to pull out a small item out of nowhere, as long as it is something your character would have, and Wild Talent, which lets you perform an untrained skill, and learn it permanently with an enhancement.
Several supplements have expanded on these rules to specifically model this trope, and explain the rationale for it in drama/action/comedy.
GURPS also includes psionics rules, including powers similar to this that allow a precognitive character to retcon a counter to a situation they would have foreseen, so long as it doesn't contradict events that have already happened. So a character who is captured and hauled before the Big Bad could have a derringer on them... but only if they haven't actually been searched "on camera".
Toon, another title by Steve Jackson Games, also features Gizmos, which can be set to be whatever you need at a specific time. In practice, this usually means anvils.
Warhammer 40,000's Eye of Terror campaign involved an Ass Pull from Games Workshop. Namely, the Eldar came in just behind the guard and marines yet ended up losing Eldrad and all the Blackstone Fortresses - i.e., the sort of result that might be expected from coming in last. And the loss of Eldrad may or may not have happened, as Games Workshop took down the .PDF with the results from their site, and materials published after the Eye of Terror campaign speak of Eldrad as alive. He is still included as a fieldable character in the Eldar codex published afterward.
The main result also became this, as GW had to reconcile the forces of Evil coming first in the normal game but being utterly smashed in the specialist games (specifically Battlefleet Gothic). Eventually it was decided that the baddies managed to take half of Cadia, but are now cut off in a Stalingrad-style pocket due to the Imperium smashing their spaceborne assets.
The Eye of Terror campaign wound up with the Imperium getting really screwed over. Not just with Cadia being overrun by Chaos though. The Orks campaign was supposed to be stopping the Tau from increasing their empire, and allegedly the Ork fanbase was pissed at this, so they co-ordinated and focused all their efforts on a system called Thracian Primus (which appeared in Eisenhorn), which has a Forge World on it, long story short, the Orks essentially smashed it to bits in what they called "The Green Kroosade", and renamed the world Mo'Dakka. As a result the Tau expanded unopposed. Furthermore, the Eldar and Dark Eldar managed to curbstomp the Thousand Sons, locking them out of the webway and preventing them ever reaching the Black Library, and supposedly Commorragh got sealed off into a pocket universe for good. Games Workshop then decided to retcon the whole thing to right before the campaign started for whatever reason out there. The forces of Disorder being a lot more organised certainly helped their cause.
The resolution of the Storm of Chaos in Warhammer Fantasy was similarly filled with randomness and has also been mostly ignored since. In fact, the entire Storm of Chaos campaign appears to have been completely reset, as all the army book timelines printed since then, if they even mention the forces of Chaos, merely end on an ominous note about how the forces of Chaos are massing under Archaon's banner and will soon sweep southwards. With the obvious exception of Archaon himself, most of the other Storm of Chaos characters have been completely erased from the setting (poor Valten)
This is a common thing in the aftermath of any Games Workshop campaign, as technically speaking the in-setting outcome is supposed to be based on the results of the real-world games. This is a noble goal, but incredibly hard to accomplish without completely changing the setting. Games Workshop do not really want to change the setting, but this won't stop them from promising that the latest campaign will "have large-scale effects on the world." This causes problems when, for example, The Storm of Chaos mentioned above was won (by quite a margin) by the forces of evil. Rather than trying to work that into the setting, strongly crippling at least one major faction (the Empire was in ruins by the end) and having to rewrite every army book to represent the new plot, they just decided that the Storm of Chaos was an alternate reality and continued as if nothing happened.
Mutant City Blues indie system has a special stat named Preparedness. Specifically called for to make convenient ass pulls for players in an assumption that the character had thought it out beforehand.
In Mutants & Masterminds, you can spend hero points to pull stuff out of thin air. For example, your superhero Hypervolt might spend a hero point to pull some some smoke grenades from his utility belt, to pick up that Improved Grapple feat when you really need to grab the enemy, or even buy an Alternate Power feat for his electrical control and turn out to be able to create an aura of lightning around himself.
Where did they come from? Oh! There you are my dear. Put those in some water, will you?... And then wash your hands.
Super Smash Bros. Brawl: When you are about to fight the final boss, Tabuu, in Brawl's Subspace Emissary story mode, Sonic the Hedgehog appears out of nowhere and smashes the boss' wings, significantly weakening him.
Fire Emblem Jugdral: In Geneology of the Holy War, a seemingly Well-Intentioned Extremist, King Trabant of Thracia, murders The Hero Sigurd's sister Ethlyn and her husband Cuan, the rulers of the Manster District, and he kidnaps their infant daughter Altenna and raises her as his own. While his acts are heinous and he clearly is working against Sigurd, what we do know is that he also seeks to improve the welfare of his country. The midquel, Thracia 776 (where Cuan and Ethlin's son Leif is the main character), reveals that the Loptyr Sect manipulated Trabant into killing Cuan and Ethlin. It comes off as kind of cheap.
The "twist" of M'uru allowing himself to be captured and drained by the Blood Elves would have far more effective if everything in the game hadn't pointed in the opposite direction (M'uru making active attempts at escaping, the Blood Elves becoming increasingly violent and arrogant about their stolen abilities, etc). One of the Blood Elf leaders, Lady Liadrin, pulling a complete 180 in terms of personality in the space of three seconds didn't help the plot development seem any less of an Ass Pull. Not that it makes it much less silly, but some people were expecting that exact plot twist from the day blood elf paladins were announced. There are forum discussions and fanfics theorising it well before the actual events occurred in-game.
The original lore of the Blood knights was an Ass Pull as well. The light (power from faith), suddenly being able to be siphoned like gasoline from the recently created Naaru. It's so bad that the above change could be considered an Author's Saving Throw, meaning the explanation is "this stunt worked because said Naru was letting it work." And when M'uru is kidnapped, somehow they still manage to stay Blood Knights, and new player character paladins can still be created.
Likewise, the whole notion of the Blue Dragonflight suddenly turning hostile and thus providing a convenient source of killable mobs in the Northrend expansion is a shameless ass pull. In the preceding Outland expansion said Blue Dragonflight actually helps you defeat the Final Boss...
Mortal Kombat 9, the ending where Quan Chi reveals that Shao Kahn sold him the souls of fallen Earthrealm warriors makes very little sense when you consider that it was never shown that such a deal was made and that Kahn should have no jurisdiction over souls that aren't his. It's just a plot device that the writers pulled out of their rectums without even explaining it. Also considering that the Netherrealm has been described only being able to accept evil or tainted souls. A rule that was VERY CONVENIENTLY ignored here in order for this to work
This can be applied to the ending of Legendary, wherein Deckard's Signet is revealed out of entirely nowhere to be the blueprint for the construction of another Pandora's Box.
In Mass Effect 3, the Synthesis ending. Throughout the entire game, the player is repeatedly told by opposing factions that the only options in dealing with the Reapers are to either destroy or subjucate the Reapers, but the last three minutes of the game suddenly declares that there's a third "preferred" option; Synthesis, which was only previously mentioned in the original game by Saren, and treated as a monstrosity that has seen him become a mere puppet of Sovereign; furthermore, Synthesis is depicted as making organics & synthetics into techno-organics, rather than Saren's use of cybernetic implants, and somehow accomplishes the task of making everyone into hybrids by simply shooting a green beam throughout the galaxy, which apparently changes the fabric of life by, according to the Catalyst, modifying all "synthetic" thought processes and turning every single organic being into cyborgs. Note that the Synthesis ending is not alluded to or available if you have a low enough effective military strength.
Cave Story: Killing the final boss causes the floating island to fall. However, killing the True Final Boss causes the island to stop falling. Sloppily handwaved with something vague about "negative energy".
And those three brief sentences are all the information the game gives you on this matter, in stark contrast to the nicely fleshed-out backstory of the Final Boss and the True Final Boss themselves.
A more literal interpretation exists in Bomberman. There are rumors on where they get all those bombs, and 'really deep pockets' doesn't cut it.
LEGO Island 2 brings us the constructopedia. It's a book that supposedly holds the island together, and if a page is torn, the building assigned to it falls apart. It's not mentioned anywhere in any of the other two games in the series, nor is any hint of its existence made until the Brickster needs it. It's just a simple Plot Device that was pulled out of thin air so they could give the Brickster a reason to pull the entire island apart in one fell swoop. It's even more glaring if you played the first game, where actually goes through the trouble of tearing the buildings apart individually.
Collar 6 manages this when Butterfly conjures a SIXTY-FOOT INFERNO OF FIRE... for a freakin' spanking contest. With no explanation except that the comic started taking the "Fantasy" part of being a "BDSM Fantasy Comic" literally, and a hasty explanation a few strips later.
Sixx defeats said column of fire with a "submissive shield," drawing from the same hasty explanation. What's worse, as Sixx is a dominant by trade, she somehow drew the power to do it from her submissives, one of whom had no idea what was happening at all.
Parodied with Vaarsuvius's familiar Blackwing in The Order of the Stick, the raven who actually is supposed to be there and visible all the time. Its popping in and out of existence lampshades how familiars (and horses, or any living or bulky possessions) are often treated in D&D sessions: Only there when they are needed, never when it would be inconvenient or difficult to bring them along.
A non-parody Ass Pull showed up later, however. The Potion of Glibness, which Elan claims he bought while they were separated despite it never being mentioned before. At least he and Hinjo went to several island states giving him plenty of opportunity to buy it.
A certain cool dude was assumed dead some time ago in Homestuck but later turned up alive with little explanation. It's unclear why Davesprite's missing wing and yellow blood weren't seen at the scene of his presumed death. However, an earlier event could be interpreted as foreshadowing of his survival. Jade sees through her spectaGoggles that there are 13 Daves in the incipisphere, including Davesprite. But when one (other than Davesprite) dies, the count goes down to 12.
Dirk's Auto-Responder pulls a minor one, although it references the trope by name. "The algorithms are guaranteed to be 96% indistinguishable from DS's native neurological responses, based on some statistical analysis I basically just pulled out of my ass right now."
In early strips of Questionable Content, the relationship between humans and their Anthro P Cs is clearly that of owner-and-possession. A few thousand strips later, the creator finally noticed that, if the Anthro P Cs were really intelligent, this was slavery. Out of nowhere, it was made clear that the relationship is a non-binding "friendship" contract, and the term "owner" became offensive. This makes some of the early strips (where Pintsize appears to have no say in what is done to him or his chassis by Marten, Faye, or the government) kinda creepy.
The Electric Wonderland comic "The New Adventures of the Nettropolis Narvel" contains the most unpredictable ending that Peter Paltridge could think of for a love story, using a variation of That Was Not A Dream to subvert a Truman Show Plot. In order to keep it a surprise, he kept foreshadowing to a minimum.
Avatar: The Last Airbender has a base-breaking example in the series finale, where Aang, after struggling for some time over whether or not he should kill Firelord Ozai, is suddenly able to Take a Third Option and strip his bending from him using a previously unknown and largely unforeshadowed technique known as Energybending.Word of God from a post-series artbook states that they'd planned on this story development well before the show was even picked up by a kids network. It doesn't really negate that even though there's a lot of hints that Aang could find an option like this, it is a very sudden and last minute development.
In the Book 2 finale of The Legend of Korra, during Korra's battle with a merged Unalaq and Vaatu (Dark Avatar), Jinora enters the battle with a glowing orb of light that inexplicably illuminates a blinding light onto Republic City and reveals Raava's light energy inside the Dark Avatar. Korra is able to extract the light from him and revive Raava. While it was shown that she went back to help Korra after Tenzin saved her in the Spirit World, how she got to Korra or what she even did, much less how she did it, isn't explained. Or even acknowledged. At all.
There are so many Ass Pull moments that go in favor of the good guys, it is annoying. The Sword of Omens in particular seems to gain new powers every episode. As Mumm-Ra once said, it's always used to "pull [Lion-O's] fat from the fire." Whenever the good guys are in a bind, it's always the Sword of Omens that saves the day.
Apparently, Cheetara has untapped extreme power. All that one has to do is piss her off royally. Then, she's capable of exuding brilliant rays of psychic energy that can disable a mobile fortress, knock the good guys out of a trance, and destroy machines. What?
Even the Big Bad Mumm-Ra has his own Asspull moments. There are moments in the show that Mumm-Ra seemed to be killed off for good, but he somehow comes back:'
Fighting a Genie underground, causing a cave-in that traps them both.
Lion-O defeating Mumm-Ra in his final day of the Anointment Trials. It seemed permanent.
Mumm-Ra trying to open the Star of Thundera, which causes a massive explosion that Mumm-Ra seemed to be consumed by.
Even when the Ancient Spirits of Evil get sick of Mumm-Ra's failings and give him an ultimatum to kill off the good guys or else he'll be banished from Third Earth. As expected, Mumm-Ra fails and gets exiled. What happens next? He ends up on New Thundera.
In The Fairly OddParents, some of "Da Rules" seem to be made up on the spot to make sure Timmy can't just unwish his problems (all vocal wishes must be made in the voice of the godchild, no breakfast wishes after 10:30am, etc.). Most of Da Rules/the fairies' abilities do not apply to other episodes. Examples:
The No wishing for true love or wishing to break it line? Apparently this does not count at the end of "Wishology."
So the children learned how to function as a society, and eventually they were rescued by... oh, let's say Moe.
Also lampshaded with Batman's 'carousel reversal spray'.
On Codename: Kids Next Door, the resolution of Henrich's plotline, revealing he was once a girl that got the Gender Bender treatment thanks to a magic spell is largely believed to be this, since it was never truly foreshadowed outside the often cited Noodle Incident that was revealed to be the above incident. Since it aired in the last season, it's largely seen as a half baked way to end Heinrich's plot before the series ended.
The Galactic KND is also seen as this, as well as the revelation that aging in the KND universe is an actual disease.
Likewise, quite fans dismiss Chad's claim that he was Good All Along and was actually continuing to help the KND (and Sector V in particular) while he was within the ranks of the Teen Ninjas, to be this. considering the fact that ever since his Face-Heel Turn at the end of the 2nd season, all we ever see Chad do was help in attacking the KND, you can probably understand few people buy his sudden pleading of innocence
On the Total Drama series, Chris is an in-universe master of this trope, constantly coming up with new rules and conditions to keep the Show Within a Show interesting.
From Family Guy, right after Stewie has cut open a camel's stomach and climbed inside to keep from freezing to death:
On The Cleveland Show, Terry being in an extended homosexual relationship. While the possibility of Terry being gay actually WAS foreshadowed more than once, Terry being in a committed relationship at all counts as an Ass Pull because his relationship was implied to have started before the show, but he has seduced and had sex with various women in the first season.
While not a big offender in terms of plot, Wolverine and the X-men has an asspull in the fights between Wolverine and Sabertooth. Since a fight between two guys with healing factor and razor sharp weapons would be far too messy for a children's cartoon, their fights end up being relatively anti-climatic. The asspull comes in their first encounter when Sabertooth pulls a giant taser gun nearly half as big as he is out of his cloak, despite there being no bulk or any sign of it when you can peek into his cloak before. Making it look like he actually pulled it out of his rear end.
In an episode of Inspector Gadget, there is an evil mastermind who has analyzed every one of Gadget's gadgets and determined that the way to kill him is to lock him inside a furnace and turn it on. This initially appears to work, but then Gadget uses a new weapon never seen before (or after), a hand holding an aerosol can of freon comes out from the top of his hat and sprays the walls out of the room, putting the furnace out.
In El Tigre the Titanium Titan gets back in White Pantera's good graces by promising not to hurt his son El Tigre, even under the influence of Pantera's Lie Detector boots. Just when it seems like he's really changed, he goes back to his old Ax-Crazy self. Turns out he was wearing "a truth-proof vest."
Redakai with the Cataclysm Stone. At first, they're afraid to touch it due to the potential of it exploding and causing a second Cataclysm, but by the end of the episode they just freeze and shatter it without any foreshadowing or indication that it would work.
Another episode where Maya is acting Brainwashed and Crazy due to an evil-infusing attack used by the villains. Not only do the others figure out what's happening with no prior knowledge, they figure the way to fix it is to use the same evil-infusing technique that caused her to have her Face-Heel Turn in the first place (a technique named after the villain, no less...). Rather than the logical conclusion that an additional infusion of evil would just make things worse, thanks to their Designated Hero status, Maya is cured.
Actually rather common, now, usually having to do with Ky's "Inner Kairu".
W.I.T.C.H. has a pretty good one near the end of season one. Cedric and his men have the Guardians (and a tag-along Matt) trapped on a snowy cliff and the only way out is if Will forks over the Heart of Candracar. What does she do? Suddenly creates copies of the Heart and make them try to find the real one (which none of them were). This was during the time Will was pulling Badass Normal duty and before Greg Weisman stepped in and rewrote the rules to make sense.
The episode "N is for Narcissist" had one moment where the girls had to be transported away through a portal during a car wash but couldn't disappear unannounced or it would look like they were skipping out on their jobs. Blunk suddenly asks the girls to give him their shoes, and then wears them obscured from view so that only the shoes are visible, while throwing his voice to make it look as though the girls never left. Consequently, the whole group of girls are stuck barefoot on the other side of the portal, having been forced to shed their socks because they would get torn up without shoes...
South Park had the ending to "Ass Burgers", where status quo is suddenly returned with Stan's parents getting back together.
Done in one episode of American Dad! where the family's new dog plays in the street and avoids being hit by a car, only for a hot air balloon piloted by pirate cats to land on top of the dog from nowhere. The accident sets up the plot.
Another episode has Stan somehow escape (off-screen) from a gang of violent drug dealers with the help of his pet mouse.
"Cheesers came back."
As an in-universe example, the plots of most of the movies in Home Movies are held together with chewing gum and ass pulls.
The way the plot involving the Orb resolves in The Venture Bros.. In a flashback where the Orb is introduced, Sandow appears to have killed Lloyd Venture to stop him from using the Orb. However - and this isn't revealed until Phantom Limb gets his hands on the Orb a season later - he didn't actually kill Lloyd, he just broke the Orb, preventing the doomsday device from being used.
Megas XLR used Ass Pulls as a source of comedy, with the titular Megas often having buttons that are labeled as being pretty much activating the "save the day" function. Of course, it didn't always exactly pan out the way you expected.
The climax of My Little Pony Equestria Girls reveals that Twilight doesn't even need the other five elements to be present to tap into their power; Seems like the power of the bond Twilight shared with the human versions of her friends (and she's known these humans...what, like two days???) was sufficient to not only allow Twilight to reclaim the powers of the Element of Magic but also summon the powers of the other five elements...which has no basis in the show's actual canon. Sort of but not really justified by the complete lack of any explanation on how the Elements actually work in the show anyway.