History Main / GlitchEntity

* The original ''VideoGame/MortalKombat1'':
** While it did ''not'' have a character named Ermac ([[UrbanLegendOfZelda it was an April Fool's joke]]), the game ''did'' give us Glitch Reptile and Silver Goro, two glitch characters that trigger during the game's three Endurance Matches in one-player mode. Glitch Reptile occurs when you do the trick to get to Reptile during one of the Endurance Matches; you'll fight two Reptiles as a result, but the second Reptile will be a graphically glitched version of random characters in the game. You get Silver Goro when you perform a fatality on the second opponent of the last Endurance Match with Raiden or Sub-Zero, then throw your projectile at Goro as he falls from the top of the screen. Do it right, and his colors will be glitched to a weird silver for the remainder of the round. Good memories, good memories...

* The character models in the UsefulNotes/PlayStation2 ''Franchise/{{Rocky}}'' game can glitch up horribly, resulting in such things as Clubber Lang having one or two of his legs coming out of his head.
-->'''WebVideo/TheAngryVideoGameNerd''': [[NightmareFuel It's a Clubberfuck!]]

[[caption-width-right:240: ''Go ----!'']]

** While it did ''not'' have a character named Ermac ([[UrbanLegendOfZelda it was an April Fool's joke]]), ''did'' give us Glitch Reptile and Silver Goro, two glitch characters that trigger during the game's three Endurance Matches in one-player mode. Glitch Reptile occurs when you do the trick to get to Reptile during one of the Endurance Matches; you'll fight two Reptiles as a result, but the second Reptile will be a graphically glitched version of random characters in the game. You get Silver Goro when you perform a fatality on the second opponent of the last Endurance Match with Raiden or Sub-Zero, then throw your projectile at Goro as he falls from the top of the screen. Do it right, and his colors will be glitched to a weird silver for the remainder of the round. Good memories, good memories...

[[caption-width-right:240: ''What will ---- do''?]]

** There's a white recolor of Knuckles in ''VideoGame/KnucklesChaotix'', who the game calls [=***=] (a row of ten asterisks); since this is completely unpronounceable, fans nicknamed him [[http://sonic.wikia.com/wiki/Wechnia Wechnia]] (derived from White Echidna). He's actually leftover data from when Tails was cut from the game early in development; he no longer uses his own art, name, or palette, leaving the game to display Knuckles with an unpronounceable name and Mighty's palette. Playing as Wechnia is as simple as selecting him in the hidden level select. Performing certain actions with him will crash the game -- even merely touching the ground is sometimes enough to cause a crash.

** An official Pokemon called Porygon-Z is a LivingProgram which has erratic behaviour apparently due to whatever was in the Dubious Disk that's used to evolve one having a programming error.

* ''[[VideoGame/PokemonDiamondAndPearl Pokémon Platinum]] introduces Porygon-Z, an evolution of Porygon2 that was supposed to improve Porygon's initial design and programming even further, allowing it to operate in alternate dimensions. However, the data on the Dubious Disc[[note]] The item that Porygon2 needs to hold during a trade to evolve it into Porygon-Z.[[/note]] corrupted its original code, causing it to act erratically. Some even wonder if Porygon-Z can actually be considered an evolution of Porygon2.

*** ''VideoGame/PokemonXAndY'' has these as well. These glitch Pokémon don't have official names, [[https://bulbapedia.bulbagarden.net/wiki/Generation_VI_724%2B_glitch_Pok%C3%A9mon but most of them reuse Bulbasaur's model]] (with some exceptions).

[[folder:Video Game Examples]]
[[AC:Real Life Examples]]

** ''[[VideoGame/Sonic3AndKnuckles Sonic 3 & Knuckles]]''

* ''VideoGame/SuperPitfall'' often has random sprites appearing at the edge of the screen, including miscolored copies of Pitfall Harry that WebVideo/TheAngryVideoGameNerd refers to as "The ghost of Pitfall Larry" and "Pitfall Gary"
* ''VideoGame/TheLegendOfZeldaALinkToThePast'' has a mysterious invisible enemy called the ghost of Misery Mire that were an UrbanLegendOfZelda that turned out to be true. Investigation of the game's code revealed that the ghosts are actually Kus that are glitched due to being placed on the wrong type of ground tile. Kus can only exist on deep water tiles, but a few have been placed on shallow water. They can't attack but can be killed, although doing so may cause other glitches depending on what weapon was used.

** The SNES version of ''Ultimate [=MK3=]'' has one of these in Tournament mode. Do Random Select and the cursor may land on the Random icon. This creates a "character" that appears to be the leftover data from Sheeva after she was DummiedOut (sometimes called "Ghost Sheeva"). She's represented as only a few blood pixels (or sometimes nothing at all); some characters can't hit her at all, and she's capable of extremely damaging attacks. Oddly enough, you can perform Fatalities on her - she even still has her Babality sprite! - but it's very hard to do anything to her without crashing the game.
* ''VideoGame/StreetFighterAlpha Anthology'''s [[EasterEgg hidden bonus game]] Hyper Street Fighter Alpha brings us [[SecretCharacter hidden versions]] of Alpha 2 M. Bison and Sagat with scrambled glitch sprites. They both share a partial Evil Ryu moveset, have no super meter, and cannot be hit while standing still.

* If you get more than 10 lives in ''VideoGame/SuperMarioBros'' it appears that the game "rewards" you on the start level screen with a crown in the place of the tens digit (crown-3 for 13 lives, etc). This is actually just random graphical glitch based on the programmers’ rather lazy assumption that no one would ever get more than nine lives. Once you get more than 20 lives numbers disappear altogether and the digits are replaced with random chunks of nonsense. The chunks always appear in the same order, however, meaning some people have managed to decipher the "code." In later games, such as VideoGame/SuperMario3DWorld, this glitch was [[AscendedGlitch put back in]] as a legitimate feature.
* A couple of these can be seen in the DummiedOut "lost levels" of ''VideoGame/SuperMarioBros3'', such as a Koopa with Chain Chomp sprites, as well as in certain ROM hacks. With the help of Game Genie codes, you can also create strange power-suits. One of the weirdest turns the player character into a conglomeration of blocks that can swim in the air (a Lakitu Cloud on the map screen).

* [[https://zelda.gamepedia.com/Glitches_in_The_Adventure_of_Link One glitch]] in ''VideoGame/ZeldaIITheAdventureOfLink'' lets you travel to earlier dungeons, only using the graphics from later dungeons, enabling you to do things like see unused window graphics if you go from a dungeon that had no windows to one that did. However, this also results in the boss of the dungeon you're visiting being pieced together from the sprite of the boss of the dungeon you were in before, as can be seen in [[http://youtu.be/wm8008y41_0?t=5m43s this video]], just under six minutes into the video.
* The ''VideoGame/FinalFantasyI'' UsefulNotes/GameGenie code VYUOKITE allows you to select from ''244'' of these at the beginning of the game. A large number of those are automatically killed when used, but a surprising number are actually usable.

* When [=PS2=] [[UsefulNotes/{{Emulation}} emulators]] became almost fully functional, a lot of [[DummiedOut dummy data]] was found in ''VideoGame/FinalFantasyX''. This included several weapons, including a [[VideoGame/FinalFantasyVII buster]] [[https://www.youtube.com/watch?v=gom-qajs__A sword]], but they're very glitchy and crash the game in most cases.
* ''VideoGame/TestDrive Unlimited'' has a neat-looking [[https://www.youtube.com/watch?v=eHoFYvBBqwg car]] substituting for any corrupted car in your save file or game installation. It looks somewhat like an [[CoolCar Alfa Brera]] and [[DevelopersForesight clearly has had a lot of work put into it]] for something that is only supposed to appear in case of a fatal flaw in the game.

* In ''VideoGame/LostIsle'', there's a Gleeok in Bhalstok Castle, but, due to a palette incompatibility, it displays as an all-black "Shadow Gleeok." Seriously, this guy is almost as cool as Ashura...

* The bosses from ''VideoGame/StreetFighterII'', even though they appear in normal gameplay the ''World Warrior'' versions have always been Glitch Entities in their own right. In ''World Warrior'' they behave very differently from the playables and can't be controlled by the player even if they are chosen through cheats. It was discovered later through being manually fixed to be controllable they had quirks fighting each other or just being controlled that didn't apply to the regulars. Balrog couldn't duck or jump over Sagat's high tiger shot, Vega goes abnormally high when jumping off the cage from his BG when battling another boss, and Balrog also had uncancellable transition frames crouching and standing up.
* In ''Franchise/StreetFighter'' specifically ''III: New Generation'' a beta version of Hugo, who wouldn't officially debut until the next game, exist in the game's data. This version can't attack, glitches out easily, and when walking has numbers next to his character model. Strangely he also comes with a version of his stage that WOULD debut next game that features events that were removed in ''Second Impact'' such as transitions from round one and two.
* In ''VideoGame/WizardsAndWarriors'' a glitch exist where the stage's weapon can be taken with the player into the next round. Usually it is taken away when a player gets a piece of the IronSword. Effectively the Windbane could be taken up until late level 3 but has to be replaced since the stage's boss can't be hit with the weapon's arc but as it isn't meant to appear past level one the shots can look like glitchy messes (but still work as intended).

[[AC:In-Universe Examples]]

* In ''VideoGame/DevilSurvivor2'''s ''Record Breaker'' arc, [[spoiler:Miyako was brought into being as a replacement for a character who pretended to be RetGone, but wasn't, and was merged with the EldritchAbomination Cor Caroli during universe generation. Her simultaneous existence with Yamato breaks the laws of the universe, making it possible to destroy Canopus, the divine guiding order of the entire universe.]]

* [[VideoGame/DotHackR1Games .hack//MUTATION]] introduced the Net Slum, which are made of and populated entirely by junk and garbage data given form. Quite notably, while all player character data are rendered in 3D, some sentient AI within the Net Slum are simply 2D sprites, or 3D models with missing meshes.

[[folder:Non-Video Game Examples]]
[[AC:{{Anime}} and {{Manga}}]]

[[AC:Fan Works]]

[[AC:Films -- Animated]]

[[AC:Films -- Live-Action]]
* ''Film/{{Inception}}'' has stray projections that get in the way of dreamsharing. There's Mal, a violent, nigh-unstoppable projection born from Dom's guilt, who takes the form of his dead wife. She rages through the dreamscape, generally messing everything up for the crew. There's also Dom's kids, who are less violent, but always faceless and whose appearance usually indicate danger.

[[AC:Webcomics]]

[[AC:WebOriginal]]

[[AC:WesternAnimation]]

[[AC:RealLife]]
* One of the theories for why we dream is that the brain mistakenly interprets vital maintenance information as sensory stimulation while asleep, which would explain why dreams are often so weird. For example, the theory that dreams of flying/floating come about as the brain's best attempt to reconcile the sensation of moving about in some way with the fact that it can't actually sense your arms or legs moving because REM sleep stops you from being able to do so.

** There's a white recolor of Knuckles in ''VideoGame/KnucklesChaotix'', who the game calls [=***=]; since this is completely unpronounceable, fans nicknamed him [[http://sonic.wikia.com/wiki/Wechnia Wechnia]] (derived from White Echidna). He's actually leftover data from when Tails was cut from the game early in development. Playing as Wechnia is as simple as selecting him in the hidden level select. Performing certain actions with him will crash the game -- even merely touching the ground is sometimes enough to cause a crash.

* ''VideoGame/FiveNightsAtFreddysSecurityBreach'' gives us "[[FanNickname Giga Monty]]". During the Showtime quest, Montgomery Gator will appear in the atrium operating a spotlight from the top of a roof. Using SequenceBreaking, players can leave and enter the Atrium several times while Monty is there. Every time the player leaves the Atrium, it's unloaded, but Monty is not, causing him to fall through the now non-existent roof and land on the ground. This gives him a viable path to catch Gregory, which he doesn't have while on the roof - and for some reason, this version of Monty contains a simpler, but much more dangerous AI script that simply [[SuperPersistentPredator moves towards Gregory at all times once alerted by a S.T.A.F.F. bot, ignoring line of sight, Gregory being in Freddy, and everything else]]. Giga Monty lacks the AI to actually detect [[PlayerCharacter Gregory]] and become alert, but triggering a S.T.A.F.F. Bot will alert him, and he will never give up the chase, cannot be tricked by climbing onto tables or into Freddy unlike the other animatronics, and will push Freddy into the wall until they either catch their target or Freddy loses all his power and jump-scares Gregory himself. Even [[spoiler:destroying Monty during his boss fight and leaving him in his "[[HarmlessVillain Shattered]]" state]] will not stop Giga Monty, as the game doesn't remove him when Monty is defeated (since he should normally never be there by that time). And to make this even worse, once Monty has fallen through the roof, if you return to the area, the game thinks that the spotlight operator Monty is missing and respawns him on the roof - but without removing the old one. This new Monty will also fall through the roof if the area unloads, so this can be repeated multiple times, spawning a new Monty each time; meaning that as soon as a S.T.A.F.F. bot is triggered, an unstoppable army of robot alligators is released in the Atrium to hunt down Gregory forever. It's a GameBreakingBug if you're not planning for it, but definitely a GoodBadBug if you are.

*** [[VideoGame/PokemonXAndY]] has these as well. These glitch Pokémon don't have official names, [[https://bulbapedia.bulbagarden.net/wiki/Generation_VI_724%2B_glitch_Pok%C3%A9mon but most of them reuse Bulbasaur's model]] (with some exceptions).

[[AC:Film]]

* ''WesternAnimation/WreckItRalph'', which is about video games at an arcade, has Vanellope Von Schweetz, from the racing game ''Sugar Rush''. She mostly looks like an ordinary Sugar Rush character, but glitches in and out (replacing her normal appearance with lines of code) whenever she's emotionally compromised. It really sucks to be her -- she's a bullied outcast, not allowed to race despite wanting to be a racer, and she has to live in a DummiedOut bonus level. [[spoiler:She is actually a real and intended character in the game, but was turned into a glitch by Turbo, who disguised himself as King Candy to take her place as the game's ruler.]]

* Milo from ''VideoGame/BuddySimulator1984''. Right from the moment you meet him it's clear there's something off about him, as the text refers to him with the name and species of your selected "favorite animal" despite clearly being a dog, with his real name only being revealed by a glitch later. For most of the game he follows you incessantly, utilizing clipping and OffscreenTeleportation to bypass obstacles, but is otherwise harmless until you get to the FinalBoss's lair, whereupon [[spoiler: he proceeds to crash the game ''twice'' and gets fused with Groncho, becoming the PostFinalBoss]]. The reason for his glitchiness is actually fairly realistic, as hidden files imply he's [[spoiler: a borrowed asset from another game that didn't get ported over properly]].

* In ''VideoGame/DevilSurvivor2'''s ''Record Breaker'' arc, [[spoiler: Miyako was brought into being as a replacement for a character who pretended to be RetGone, but wasn't, and was merged with the EldritchAbomination Cor Caroli during universe generation. Her simultaneous existence with Yamato breaks the laws of the universe, making it possible to destroy Canopus, the divine guiding order of the entire universe.]]

* ''VideoGame/{{Undertale}}'' has the hidden character of Dr. W.D. Gaster. You have to mess around with the "fun" values in the game's coding to learn anything about him. [[spoiler:He was the royal scientist before Alphys, and has created the CORE, but he was scattered across space-time after falling into one of his inventions, with it being often theorized [[RetGone all memory of him has been erased wih him]]. It's implied that he's ''aware'' to some degree and forced to watch the world functioning exactly the same without him. Oh, and did we mention that a later patch ''removed'' the need to mess with the files, randomly allowing his followers, [[AmbiguouslyRelated and possibly even Gaster himself]], to appear in non-edited worlds?]]

* ''Webcomic/{{Homestuck}}'''s Lord English is implied to be this, [[spoiler: being the result of two players who share a single body entering a SBURB session that was designated for one player only, something that was explicitly stated to be impossible]]. Appropriately enough, [[spoiler: he's even caused the game to glitch, causing spans of MissingTime for the protagonists.]] [[FromBadToWorse It gets worse]]. [[spoiler: A single-player session]], though radically different from the base game and incredibly difficult to set-up, can have one of two possible outcomes: Either the player 'gives up all ambition' and dies, but becomes instrumental in stopping a great evil... or tackles an incredible challenge and gains unconditional immortality and the power to destroy anything he or she wishes. The only way to stop them? ''[[LordBritishPostulate Glitching reality]]''.

* The Wiki/SCPFoundation: [[http://www.scp-wiki.net/scp-951 SCP-951]], an anomalous [[DarkIsNotEvil (but apparently friendly)]] video game glitch named "LUCAS" [[spoiler: AKA LOGICAL UNIFIED CENTRAL ANOMALY SYSTEM. It was deliberately engineered but flawed as it would "die" when the game ended and couldn't remember anything when the game restarted]]. Missingno gets a shout-out in a chatlog about the mysterious glitch:

* ''WesternAnimation/WreckItRalph'', which is about video games at an arcade, has Vanellope Von Schweetz, from the racing game ''Sugar Rush''. She mostly looks like an ordinary Sugar Rush character, but glitches in and out (replacing her normal appearance with lines of code) whenever she's emotionally compromised. It really sucks to be her -- she's a bullied outcast, not allowed to race despite wanting to be a racer, and she has to live in a DummiedOut bonus level. [[spoiler: She is actually a real and intended character in the game, but was turned into a glitch by Turbo, who disguised himself as King Candy to take her place as the game's ruler.]]

* ''VideoGame/{{Undertale}}'' has the hidden character of Dr. W.D. Gaster. You have to mess around with the "fun" values in the game's coding to learn anything about him. [[spoiler:He was the royal scientist before Alphys, and rumored to have created the CORE, but he was scattered across space-time after falling into one of his inventions, with all memory of him gone. It's implied that he's ''aware'' to some degree and forced to watch the world functioning exactly the same without him. Oh, and did we mention that a later patch ''removed'' the need to mess with the files, randomly allowing him to appear in non-edited worlds?]]

* Milo from ''Buddy Simulator 1984''. Right from the moment you meet him it's clear there's something off about him, as the text refers to him with the name and species of your selected "favorite animal" despite clearly being a dog, with his real name only being revealed by a glitch later. For most of the game he follows you incessantly, utilizing clipping and OffscreenTeleportation to bypass obstacles, but is otherwise harmless until you get to the FinalBoss's lair, whereupon [[spoiler: he proceeds to crash the game ''twice'' and gets fused with Groncho, becoming the PostFinalBoss]]. The reason for his glitchiness is actually fairly realistic, as hidden files imply he's [[spoiler: a borrowed asset from another game that didn't get ported over properly]].

* In ''VisualNovel/DokiDokiLiteratureClub'', removing the file of a character from the game directory will cause that character to hover between existing and not existing, only appearing in-game in bizarrely glitched ways. The reason it's not a "real life" example is that the way it happens was deliberately designed in advance. ItMakesSenseInContext.

** Among the glitch trainers is Professor Oak, who is never fought in normal gameplay, but was originally intended to be. He has a proper party programmed into the game, but it isn't used anywhere, and he's more likely to use an incorrect team instead if fought using glitches.

** Among the glitch trainers is Professor Oak, who is never fought in normal gameplay; he does have a proper party programmed into the game, but it isn't used anywhere, and he's more likely to use an incorrect team if fought using glitches

** ''VideoGame/PokemonRedAndBlue'' has the most glitch Pokémon of any entry in the series thanks to numerous programming quirks. It also contains some glitch trainers, including Professor Oak, who is never fought in normal gameplay; he does have a proper party programmed into the game, but it isn't used anywhere, and he's more likely to use an incorrect team if fought using glitches.

*** While not dangerous per se, one of the most known glitch Pokémon that require effort to encounter has an unpronounceable name consisting of glitch characters, the female symbol, and a period. This glitch Pokémon is infamous for its never ending cry, which causes the game to get stuck on the fight screen until the console is switched off, since the game can't continue until ♀ .'s infinitely long cry ends.

** [[VideoGame/PokemonGoldAndSilver Gen 2]] has a [[https://bulbapedia.bulbagarden.net/wiki/Glitch_Egg glitch egg]]. In ''Gold and Silver'', attempting to use it in battle will crash and restart the game. In ''Crystal'', you can battle with it, but as it has no moves, it will use Struggle until it faints. Every 30,720 steps, it will hatch into ''another'' egg.

** There's a white recolor of Knuckles in ''VideoGame/KnucklesChaotix'', who the game calls ***; since this is completely unpronounceable, fans nicknamed him [[http://sonic.wikia.com/wiki/Wechnia Wechnia]] (derived from White Echidna). He's actually leftover data from when Tails was cut from the game early in development. Playing as Wechnia is as simple as selecting him in the hidden level select. Performing certain actions with him will crash the game -- even merely touching the ground is sometimes enough to cause a crash.

*** Generally trying to get either Tails or Knuckles into The Doomsday through this method will make their sprites garbled up, as the game still recognizes both of them as being Sonic, who is supposed to be the only character allowed to access this level.

* ''VideoGame/SonicTheHedgehog2'' had a glitch where using debug mode to create a metric buttload of a certain object would cause Sonic's palette to be overwritten, turning him green, black, and one other color (which would often also be green or black). This miscolored Sonic, nicknamed [[http://sonic.wikia.com/wiki/Ashura "Ashura,"]] is a surprisingly popular "character", making frequent appearances in fan works.
* There's also a white recolor of Knuckles in ''VideoGame/KnucklesChaotix'', nicknamed [[http://sonic.wikia.com/wiki/Wechnia White Echidna]] (shortened to Wechnia), who's actually what's left of Tails when he was cut from the game. Playing as him is as simple as selecting him in the hidden level select. Though be aware certain actions with him will crash the game, even touching the ground sometimes.
* ''[[VideoGame/Sonic3AndKnuckles Sonic 3 & Knuckles]]''
** Has [[https://www.youtube.com/watch?v=tqi5H0Myo8c Blue Knuckles,]] who plays like a mixture of Sonic (his palettes and level routes), Knuckles (abilities), and Tails (uses his name at the end of act tally). The only ways to play as him are through hacking, UsefulNotes/GameGenie, or [[https://www.youtube.com/watch?v=m1atT6qrRLY a massive glitch in Lava Reef.]]
** Also, if you turn on DebugMode, use Stage Select in ''Sonic 3 & Knuckles'', go to the Doomsday Zone Act 1 as Knuckles and beat the level, the ending sequence will feature a palette swap of Sonic, Knuckles, and the Tornado.
** Generally trying to get either Tails or Knuckles into The Doomsday through this method will make their sprites garbled up, as the game still recognizes both of them as being Super/Hyper Sonic, who is supposed to be the only character allowed to face this level and the game's [[AnotherSideAnotherStory first]] TrueFinalBoss.
** Since the game dynamically loads enemy sprites and tiles as you go through a level, if Sonic goes too fast while in SuperMode, he can outrun the sprite loading and cause enemies or backgrounds to be garbled.

* ''Franchise/{{Pokemon}}'':
** [[https://bulbapedia.bulbagarden.net/wiki/MissingNo._ "MISSINGNO."]](short for Missing Number) from Generation I. A similarly glitchy creature has a name consisting of a quote mark, the letter M, and two [[TheUnpronounceable unpronounceable]] symbols. It has been {{Fan Nickname}}d "M-Block." or "'M" (pronounced "Apostrophe M"). The glitch is actually caused by the game trying to interpret your PlayerCharacter's name as random-encounter data.
*** Missingno., its [[http://bulbapedia.bulbagarden.net/wiki/Glitch_Pokemon glitchy kin,]] and the effects they have on the game make up an impressive amount of [[{{NightmareFuel/Pokemon}} Pokémon's Nightmare Fuel page]]. In fanworks such as ''Fanfic/PokemonResetBloodlines'' and ''WebAnimation/StarterSquad'' they're often portrayed as a form of EldritchAbomination. [[WebVideo/AtopTheFourthWall And not just in Pokémon, either...]]
*** [[GoodBadBugs Missingno. also has the benefit of increasing the quantity of the 6th item in your bag by 128]].[[note]]In short, every pokémon has two bits in memory for the pokédex to store whether you've seen and/or caught it. The seen bit for [=MissingNo=]. happens to be the most significant bit of the quantity of the 6th item, so if you have less than 128 of it, the game marks that you've now seen [=MissingNo=]., giving you 128 of the item.[[/note]] For competitive battling, this is quite the [[GameBreaker Game Breaker]]. Cloned Rare Candies + Cloned Technical Machines + Cloned Master Balls + Cloned Medicine = A team of six in the timeframe it would take to create one Pokémon without glitching.
*** Despite common belief, Missingno. and M-Block are actually relatively harmless; it only causes minor graphical glitches [[labelnote:Explanation]]The graphical glitches are caused by looking at Missingno.'s stats and can be fixed by looking at the stats of anything that isn't a glitch Pokémon[[/labelnote]] and corrupts the Hall of Fame data (and the Hall of Fame entries aren't required for playing the game anyway) [[labelnote:Explanation]]This is due to the unusually large values for Missingo.'s sprite data, causing the graphics engine to overwrite the information inside the Hall of Fame with its overflowing sprite data when it attempts to decompress Missingno's sprite into memory[[/labelnote]]. There are much more dangerous glitch Pokémon, but they require significantly more effort to make appear. Basically, a good rule of thumb to follow, is that if a Glitch Pokemon requires more effort to see or catch, it'll cause more damage to your game. [[http://www.smogon.com/forums/showthread.php?t=78267 Apparently, Missingno. might actually be leftover data from removed Pokémon, while its unpronounceable kin are "garbage data" given form.]]
*** While not dangerous per say, one of the most known glitch pokemon that requires effort to encounter is a glitch pokemon only known as the typical female symbol. This glitch pokemon is infamous for its never ending cry and some youtubers make videos of recording its cry for very long amounts of time. Some youtube video makes even have done videos using emulator tools to significantly speed up the game from the default speed and recorded for a long time just to see if there is an end to its pre-battle cry.
** 'M and Missingno. are probably the best-known examples in the series because you can encounter them without modifying the game in any way. With use of a VideoGame/GameShark and a Walk Through Walls cheat enabled, however, it's also possible to run into a number of different glitched Pokémon and trainers, many of which can do ''serious'' damage to your save file if you're not careful (or just plain unlucky). [[http://lparchive.org/LetsPlay/BreakingBlue/ This LP]] of Blue version details many of them and their effects.

** Even in the modern day, Missingno. hasn't stopped causing mischief! Not only does it return in the 3DS Virtual Console re-releases of the original games, but if the player attempts to transfer it to ''VideoGame/PokemonSunAndMoon'', it will not be let through but will shift all your Pokémon's names over by one.