->''"Your mind was a curious mix of madness and genius. I just took away the genius."''
-->-- '''Jace Beleren''', ''TabletopGame/MagicTheGathering'', [[http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=266487 Flavor Text for Mind Sculpt]]

In short, a weaponized IdiotBall.

One of the most effective ways to deal with an enemy is to rob them of their greatest weapon - their mind. This trope is a subtrope of MindRape, an intentional attack on someone's intellect. In layman's terms, deliberately making someone stupid.

This trope can take many forms. It can be temporary or permanent. It can be achieved through magic, surgery, or weaponised PhlebotinumInducedStupidity. It can have any number of degrees of severity, ranging from simply taking the edge off the victim's reasoning to full-on infantilisation or even reducing them to a drooling vegetable. Finally, depending on the work's tone, it can either be PlayedForLaughs or be a potent source of NightmareFuel.

This attack also has a variety of uses. It can be a means of control, a way to neutralise a troublesome GuileHero or [[TheChessmaster Chessmaster]], or even a particularly sadistic torture method or FateWorseThanDeath (especially if [[AndIMustScream the victim's aware of what's happening to them]]). Some characters, in fact, use it to boost their own knowledge and intellect via a form of VampiricDraining, though this is not strictly necessary to the trope. Whatever the case, though, removing some IQ points from the target must be a deliberate purpose of the attack, not just a side-effect.

Contrast IdiotBall, PlotInducedStupidity, and TookALevelInDumbass, where it's the ''writer'' dumbing down their characters. Compare PhlebotinumInducedStupidity, which is often unintentional and possibly either self-inflicted or the result of some environmental effect, as well as BroughtDownToNormal or {{Depower}}, an event with a similar purpose used to strip away someone's physical or supernatural abilities. [[IThoughtItMeant Not to be confused with]] BrainDrain, which is about making a company or organization dumber by stealing away talented employees.



[[folder:Anime & Manga]]
* In ''[[Anime/MobileSuitVictoryGundam Victory Gundam]]'', the [[DoomsdayDevice Angel Halo]] is designed to fire a permanent Stupidity Inducing Attack at ''the population of Earth''. Definitely ''not'' PlayedForLaughs.
* ''Manga/BoboboboBobobo'':
** During the fight with Pana of Giga's Six Cyber Knights, Poppa Rocks/Don Patch summons a literal idiot ball in retaliation against Pana's Psycho Balls. However, all it actually does is make you ace an upcoming test... [[ArsonMurderAndJaywalking by CHEATING!]]
** Later on against Poet, he stabs a spike into Poet which injects the latter with a fluid that makes Poet think just like Poppa Rocks, and given how Poppa Rocks (Hell, just about any of the fighter on the good side) think, this doesn't really go well for Poet in regards to his techniques.
* Kaminari of ''Manga/MyHeroAcademia'' can potentially inflict this on himself if he unleashes too much of his electrical power in one shot.
* The Stand "Jail House Lock" from ''Manga/JojosBizarreAdventure'' reconstructs this trope; while active, it's victims can only remember three things at a time.
* Parodied in ''Manga/OnePiece'' when Luffy does "Gomu Gomu no Boh/Gum Gum Space Out" and completely clears his mind of thought so Eneru can't read his moves with his Mantra. It's not much of an "attack" as he can't fight back with it.

[[folder:Comic Books]]
* ''ComicBook/JudgeDredd'' once included a device called the 'Stupid Gun' designed to do this. [[HilarityEnsues Predictably, it fell into precisely the wrong hands]].
* One of the main subplots of ''ComicBook/IdentityCrisis'' revealed that certain members of the Justice League frequently used ComicBook/{{Zatanna}} to mind wipe villains if they ever found out things like their secret identities (or in the main story's case, to prevent Dr. Light from trying to rape the ComicBook/ElongatedMan's wife again).
* A one-shot prequel to ''ComicBook/JusticeLeagueCryForJustice'' reveals that technically the villain Prometheus was subject to this trope; recognising that it would be impossible to contain the villain in conventional prisons given Prometheus's status as the AntiBatman, Batman and J'onn J'onzz arrange to trap Prometheus by reducing him to a mentally disabled state, which he only escapes after ''ComicBook/FinalCrisis'' when J'onzz is killed.
* One Franchise/SuperMarioBros story from Creator/ValiantComics involved a new weapon from King Koopa- the Stoopid Bomb, a hair-trigger explosive that can make anyone (Except King Toadstool) mind-numbingly dumb. There's also the Smart Bomb developed to counter the Stoopid Bomb's effects, though they all get used up on one Snifit. By the end of the story, everyone, including Koopa's army, are rendered idiots, and the now-genius snifit's attempts to take over are ignored.
* In ''ComicBook/FallOfTheHulks'', the Intelligencia does it on two different levels: with a "neural anesthetizer" of their invention, they dumb down and imprison the smartest of their enemies - [[ComicBook/FantasticFour Reed Richards]], [[ComicBook/AntMan Hank Pym]], [[ComicBook/BlackPanther T'Challa]], [[Comicbook/IncredibleHulk Bruce Banner]] and Doctor Doom - effectively lobotomizing opposition.

[[folder:Comic Strips]]
* ''ComicStrip/CalvinAndHobbes'': During ShowAndTell, Calvin claims to have invented one of these- [[http://www.gocomics.com/calvinandhobbes/1991/03/15 and it's invisible too.]]
-->'''Calvin:''' I have in my hand an invisible cretinizer! One shot renders the victim a babbling simp, a dolt, an utter moron!\\
'''Calvin:''' As Ronald proves, it's quite effective even at long range.\\
'''Ronald:''' HEY!

[[folder:Films -- Animation]]
* ''WesternAnimation/{{Megamind}}'': When Megamind visits the monument to Metro Man, he reminisces about old times and brings up an "Illiteracy Ray", a rather specific variant on this trope.

[[folder:Films -- Live-Action]]
* A medical lobotomy is used for this purpose in ''Film/OneFlewOverTheCuckoosNest'' to get rid of a particularly troublesome patient -- [[spoiler:the protagonist, in fact]].
* Likewise, the impending use of a lobotomy to achieve this end hangs over Baby Doll's head throughout most of ''Film/SuckerPunch''. The original purpose is to make it impossible for her to give testimony about her stepfather's crimes, though, rather than to make her stop causing trouble in the institution.
* In ''Film/TwoThousandOneASpaceOdyssey'', Dave Bowman pulls a rare lethal version on the [[AIIsACrapshoot rogue computer]] HAL 9000, removing its memory modules until its "brain" shuts down. Despite the machine being a clear antagonist, the sequence is remarkably upsetting.
-->'''HAL:''' Dave. My mind is going. I can feel it. I can feel it. My mind is going. There is no question about it. I can feel it. I can feel it. I can feel it. I'm a...fraid. Good afternoon, gentlemen. I am a HAL 9000 computer...
* In ''Film/SuperMarioBros'', Koopa uses the tactic to [[HollywoodEvolution de-evolve]] his opposition into mindless Goombas.
* In ''Film/RockyAndBullwinkle'', the villains plan to release Really Bad Television, a series of TV shows so horrible that anybody who watches them becomes a mindless idiot. As per usual (see the regular series below) Bulwinkle is unaffected.

* John Coffey does this to Percy Wetmore in ''Literature/TheGreenMile'', not through evil intentions but to remove the threat to his friends, resulting in the guard ending up in an insane asylum. It says a lot that Coffey only does this to people he considers to be pure evil.
* ''Literature/TheDresdenFiles'':
** Used [[spoiler:by Lara Raith on [[AbusiveParents her father]], turning him into little more than a weak-willed puppet for her to control [[TheManBehindTheMan from behind the throne]]]]. To be fair, though, the victim in that case ''[[KickTheSonOfABitch really deserved it]]''.
** Also, whilst all cases so far of it doing this are accidental, [[MindControl mind magic]] has considerable potential to be used in this way. This is because (a) mind mages tend to [[TheDarkSide rapidly devolve into insane, amoral monsters]] with little regard for the people they control, and (b) mind magic inflicts ''permanent brain damage'' on its victims. Even when [[spoiler: Molly]] first uses it with the best of intentions, the fact that she has baggage with the person she uses it on leads to deeply ingrained paranoid delusions that could end up being permanent.
* In ''Literature/TheWheelOfTime'', several characters have realized that warping the World of Dreams to make their opponents stupid can be a disturbingly effective attack. When [[spoiler: Mesaana]] attempted to use this against [[spoiler: Egwene]], her defense was so strong that it broke [[spoiler:the Forsaken]]'s mind, reducing her to an infantile mental state.
* Used as a main plot point of an entire arc in ''Literature/PerryRhodan'', when extragalactic invaders did this to the ''entire Milky Way Galaxy''. Some rare few people were immune (including most of the protagonists), but civilization basically broke down right then and there because those few were usually too busy trying to keep all the morons in check and from accidentally killing themselves and each other to keep things running on the necessary scale, let alone go after the actual threat; the need to figure out what was going on and find a countermeasure drove much of the early plot. (The scale of the event was later {{justified|Trope}} in that the so-called 'Cosmic Swarms' were revealed to have been created by {{Sufficiently Advanced Alien}}s with the intent to help spread ''intelligence'' on a cosmic scale. This particular one had simply been hijacked by ambitious underlings who decided to ReversePolarity...)
* This is an ability of the Oversoul, the millions old AI that monitors humanity in Creator/OrsonScottCard's ''Literature/HomecomingSaga''. To prevent humanity from developing to a point where it can potentially wipe itself out, the Oversoul can make those who delve into forbidden ideas suddenly stupid or forgetful until they move on to something else. It takes a lot of willpower for a human being to overcome this. This ability is so powerful that at one point the Oversoul does it to ''itself''.
* Discussed in Creator/IsaacAsimov's first novel, ''Pebble in the Sky'', which revolves around an intelligence-enhancing UpgradeArtifact. At a point, the villain threatens to ReversePolarity and use the machine to reduce the heroes to vegetables.
* Duke Roger, in the ''Literature/SongOfTheLioness'' books, put magical dolls of various people who might suspect him under a veil to make them unable to really suspect him - as soon as they intended to do something or seriously investigate, their resolve would fail.
* Ted Chiang's ''Understand'' is about a man who's given SuperIntelligence by an experimental cure for brain damage. In case he ever needs to defend himself from another superintelligent person, he devises a technique to [[FlowersForAlgernonSyndrome revert enhanced minds to normal]]. [[spoiler: When he actually uses it, though, his adversary [[DefiedTrope invents a countermeasure on the fly.]]]]
* ''Literature/IllegalAliens'' features a variation with the Stop That Cannon, which fires a powerful psychic command to '''[[ExactlyWhatItSaysOnTheTin STOP THAT!]]''' at its target(s).
* [[EldritchAbomination The Worm]] in ''Literature/ShadowsOfTheApt'' induces this effect. Its minions (who are themselves near-mindless puppets of the Worm's will) carry an aura of ignorance with them at all times, and anyone who gets too close will be stripped of all advanced mechanical and/or magical knowledge. [[spoiler: This turns out to be because the Worm itself is little more than an incarnation of primordial hunger -- it doesn't understand advanced concepts, but its will is so strong that it can force its ignorance on others]].
* In the ''Literature/{{Uglies}}'' series, when you are made into a Pretty at age sixteen, they make you into a bubblehead that won't try and rebel against the entire ideal.
* Codex of ''Literature/{{Worm}}'' has the power to inflict ''permanent'' brain damage and memory loss, and [[VampiricDraining gains a temporary boost to her own mental faculties whenever she does so]].

[[folder:Live-Action TV]]
* ''Series/{{Dollhouse}}'':
** Topher does this to [[spoiler:the head of Rossum Corp.]] in the finale, using [[spoiler:the magic mind-wipey gun to give the villain Active architecture and turn him into a doll against his will]]. Hell, he's doing this pretty much in every episode, in some form or another.
** Also, the BadFuture shown in the two Epitaph episodes is the result of this being done on a massive scale. By "massive scale", we mean somewhere around 80-90% of the world's population having their minds wiped in a single instant and then being reprogrammed to mercilessly hunt down and murder anybody that wasn't wiped.
* In ''Series/BuffyTheVampireSlayer'', Glory has a [[NightmareFuel terrifying version of this]], where she basically jams her fingers into the sides of the victims head, robbing them off their sanity and intelligence and leaving them babbling and helpless. This happens to [[spoiler: Tara]], who ends up being the only one cured thanks to Willow. A side-effect of this also benefits Glory as they see Dawn in her true form, which is described as a beautiful, pure green light, and [[spoiler:Tara]] accidentally helps Glory learn Dawn is the MacGuffin because she didn't understand that vocalizing this will result in everyone dying.

[[folder:Tabletop Games]]
* ''TabletopGame/DungeonsAndDragons'':
** Basic D&D Immortals could perform Ability Score attacks against an opponent's Intelligence.
** The Yellow Musk Creeper reduces the Intelligence of its victims.
** The Feeblemind spell massively lowers the target's Intelligence.
** Psionic attacks, from Original D&D (Eldritch Wizardry) to AD&D1.
*** Ego Whip could cause idiocy when used against a defenseless psionic.
*** Psionic Blast could cause a Feeblemind effect on a non-psionic creature.
** The spell Ray of Idiocy, which reduces the target's Intelligence by 1d4+1, [[LethalJokeItem can be hilariously broken if you know how to use it]]. How? Well, having a 0 in any stat is debilitating; 0 Intelligence causes a coma. Now, all animals have Intelligence 2 or less, and many magical beasts aren't much brighter. Thus, this spell can one-shot anything from a housecat to the Tarrasque.
* ''TabletopGame/MagicTheGathering'' has [[http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=188962 Nemesis of Reason]] whose attack causes you to discard 1/6 of your deck, representative of your mind/knowledge/power. And more generally, this is the idea behind the alternate win condition of "milling." (usually associated with blue mana, which represents mental magic, among other things). When you have no more cards in your deck, you lose. This path to victory is represented by such wonderful spells as [[NamesToRunAwayFromReallyFast Mind Funeral]].
* ''TabletopGame/{{Champions}}''. The Drain power (and in older editions, Destruction and Transfer) can be used to lower another character's Intelligence, either temporarily or for a considerable time.
* In ''TabletopGame/MutantUA'', this exists as a psionic power known as "Parasit" (would be "Parasite" in English). The character increases one of his own attributes by stealing it from someone else, and Intelligence can be the chosen attribute.
* ''Franchise/{{Warhammer}}'':
** ''TabletopGame/WarhammerFantasyRoleplay'' 1st edition had the 1st level Battle Magic spell [[ExactlyWhatItSaysOnTheTin Steal Mind]], which temporarily reduced its victims to a drooling vegetable capable of doing little more than gibbering and eating grass.
** ''TabletopGame/{{Warhammer}}'' has a special rule called "Stupidity" which causes you to have to take an LD test or just wander forward. Several armies have magic weapons (such as the Wood Elf "Dragontooth Arrows") or abilities that cause a wounded model to be subject to the special rule, playing this trope literally. On the other hand, since it's on a model-by-model basis, and most models only have 1 wound, it's usually a wasted effort, but hey. Also, a high-level "metal" spell [[TakenForGranite turns an enemy into gold statues]], inducing Stupidity on nearby units through GoldFever.
** A Harlequin weapon in ''TabletopGame/{{Warhammer 40000}}'' is called the Neuro-disruptor, which "uses intricate psycho-crystalline circuitry to emit a wave of particles that disrupt the brain's neural pathways, turning the target into a drooling imbecile or killing them outright".
* In ''TabletopGame/BlackCrusade'', this trope is one of the possible effects for a Daemon Weapon. The weapon is described as having some incorporeal parts, and the attacks go right through a target. Then they become too stupid to breathe.

[[folder:Video Games]]
* ''Franchise/TheElderScrolls'':
** Throughout the series, there are spells for reducing the skills and attributes of the target; one such spell affects Intelligence. Such spells can either be cast or used to enchant items. Thus, a weapon could be designed to make the enemy more stupid each time it hits. (Useful for taking down enemy mages, for instance.)
** In ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'', there are two diseases that affect Magicka: Witbane and Brain Rot. The former slows down Magicka regeneration, the latter reduces your maximum Magicka. They are contracted from being attacked by Sabre Cats and Hagravens respectively.
* ''VideoGame/NetHack'''s Mind Flayers have an attack that reduces intelligence. They can also cause amnesia, making you forget which of your items are which.
* In ''VideoGame/ShinMegamiTenseiStrangeJourney'', [[spoiler:Zelenin]]'s Song is supposed to be so angelic, so beautiful, that anyone who hears it cannot help but lose all their will to fight and submit immediately to [[spoiler:her]]. Which is rather creepy in and of itself, but then the angels get the idea of ''weaponizing'' it to subdue corrupt mercenaries, brainwash ''demons'', and eventually [[spoiler:assimilate all of humanity]].
* 4X game ''VideoGame/{{Ascendancy}}'' includes the Intellect Scrambler, which temporarily erases the memories of the crew of the affected ship. The in-game description claims that it can "turn an experienced crew into a bunch of bumbling rookies".
* In ''VideoGame/{{Portal 2}}'', [[spoiler: Wheatley]] is an Intelligence Dampening Sphere who was created as part of [=GLaDOS's=] AI, to prevent her from killing everyone in the facility by giving her a constant stream of terrible ideas.
* In ''VideoGame/ZakMcKrackenAndTheAlienMindbenders'' by Creator/LucasArts, the villainous Caponians are using a stupidity-inducing signal over the phone networks to slowly reduce the humans' intelligence, until we're stupider than them and they can finally invade. At the end of the game, mankind reclaims its brainpower and usher in a new age of enlightenment, with telepathy and dream-sharing replacing telephones and two-headed-squirrel burgers becoming a new fad.
* ''Franchise/{{Pokemon}}'' has the Simple Beam attack, a psychic laser that [[ExactlyWhatItSaysOnTheTin changes the target's Ability to Simple]]. (Use with caution; a Simple Pokémon can be a LethalJokeCharacter.)
** A closer interpretation comes in the form of attacks such as Supersonic, which causes the Pokemon afflicted to "hurt themselves in confusion".
* ''VideoGame/FalloutNewVegas'' DLC Old World Blues features this as a central part of its plot. The Thinks Tanks, essentially a cyborg BrainInAJar, are a group of moral-less scientist who threatened to destroy the already post apocalyptic world with their experiments. [[spoiler: One of the Think Tanks, Dr. Mobius, realizes this but fails to reform his colleges, so makes them into idiots by reprogramming their robotic parts. Their stupidity serves the dual purpose of preventing them from creating more scientific hazards and preventing them from figuring out how to disable the radar fence, a feature that prevents disembodied brains (or de-brained bodies) from leaving (the think tanks think its protects the facility). Mobius then starts to play the role of an Evil {{Mad Scientist}} just to distract them so that they don't figure out that they have been made idiots, he even convinces them (without directly messing with their minds) that his robo-scorpion army is equipped with a stupidity inducing attack. ]]
** A weapon in the DLC, the Glove of Mobius, actually makes your NPC opponents stupid by reducing their intelligence stat.
* ''VideoGame/DeusExHumanRevolution'': The CASIE Aug works like this as it uses pheromones to reduce the target's logical thinking ability and directs them towards actions which will benefit you, if you convince them with the right words as well.
* The Mind Flayers in ''VideoGame/BaldursGate'' has normal attacks that reduces your Int stats and they stack. And when your Int stat reaches 0... ''you die''. Oh and did I mention that [[DemonicSpiders they can stun your party and come in packs]]?
* In ''VideoGame/EvilGenius'' some of your traps, interrogation devices and trained social minions can do it to agents of justice. It's a highly useful technique, as not only stupefied targets become docile enough to be simply escorted away from your ElaborateUndergroundBase, they will also forget any incriminating activity they've seen.

[[folder:Web Comics]]
* Inverted (with the possibility of it being played straight {{discussed|Trope}}) in ''Webcomic/KevinAndKell'', where, in one major story-arc, the [[MilkmanConspiracy Bird Conspiracy]] turns out to have an 'Intelligence Beam' with a... reverse setting. This results in one of the cast being threatened with the loss of a few dozen IQ points, and allows another (one of the denser members) to experience a bout of FlowersForAlgernonSyndrome.
* ''Webcomic/GirlGenius'': Post-VillainousBreakdown, Zola [[http://www.girlgeniusonline.com/comic.php?date=20110103 announces her intent]] to administer a... rather crude version to Tarvek. Specifically, coring out his brain with a sword in order to make him her 'zombie slave'. In her defense, she was [[http://tvtropes.org/pmwiki/pmwiki.php/Main/ItMakesSenseInContext incredibly high]] when she came up with the idea.
* ''Webcomic/EerieCuties'' had an epidemic of bimbofication thanks to a powerful artefact falling into the hands of a ''very'' perverted possessed doll.
* Likewise, a poorly timed "wish" in ''Webcomic/TheWotch'' made all non-blonde girl bimbos.
* ''Webcomic/EightBitTheater'':
** This is how the Light Warriors planned to defeat [[http://www.nuklearpower.com/2010/01/29/episode-1215-so-stupid-its-brilliant/ Chaos.]]
** Fighter himself qualifies, as just being around him for long periods of time can drain your intelligence, [[http://www.nuklearpower.com/2001/09/07/episode-076-fighter-and-red-mage-are-back/ according to Red Mage]].
* ''Webcomic/{{Narbonic}}'':
** In a non-canon Sunday strip (actually a dream of one of the readers, that the author decided to illustrate) an enemy hits Dave with an Intelligence Extractor Ray to incapacitate him. Instead, dumb Dave [[spoiler:reveals "a ''Film/ForrestGump''-like ability to observe things and turn up at the right place at the right time"]] and saves the day.
** Near the end of the series Helen invents a [[spoiler:serum that shuts down the parts of the brain that make someone a mad scientist, permanently turning them into a normal person.]] She briefly considers weaponizing it, but decides to destroy it instead.
* In ''Webcomic/DubiousCompany'', one of [[MarySue Marty]] [[ParodySue Stu's]] nebulously defined superpowers is being so handsome that nearly all women completely lose common sense in his presence.

[[folder:Western Animation]]
* JimmyNeutron uses this on himself as the entire basis of one episode, when he decides to be less of a genius. In the third ''WesternAnimation/JimmyTimmyPowerHour'' the enemy gets the edge by robbing Jimmy of his genius intelligence (and Timmy of his fairies). He wasn't as stupid as in the other example, but aside from his lack of scientific know-how he also acted much [[TheDitz ditzier]] than usual, forgetting common words and such.
* In ''WesternAnimation/{{Futurama}}'', an invading alien race of brains can sap intelligence away by their presence, which makes it easier to assimilate knowledge and destroy planets. It doesn't work on Fry, however, because he has an unusual brain quirk (which, implicitly, explains his [[IdiotHero general lack of intelligence]]).
-->'''Fry:''' I did do the nasty in the pasty.
* In one ''WesternAnimation/KimPossible'' episode, Drakken uses "Silly Hats" to avenge himself on the members of the Cerebellum Ultra-Smart Super Genius Thinking Society for [[RevengeSVP not letting him join]].
* Appears twice in ''WesternAnimation/AdventuresOfSonicTheHedgehog''. In "Grounder the Genius", Hacker creates a "Stupid Chip" as a decoy for the one with the Super Genius Program he stole from Robotnik. When Robotnik thinks he's recovered the Genius Chip, he ends up using the Stupid Chip on himself, with predictable results. Another episode had Robotnik inventing a Stupid Ray, which became the episode's MacGuffin: a crazed general thinks he can use it to make an army of brainwashed soldiers, and [[HonestJohnsDealership sleazy salesman Wes Weasley]] figures it will make it easier to sell people his worthless junk.
* ''WesternAnimation/InvaderZim'':
** In the episode "[=NanoZIM=]", Zim attempts to use this on Dib by shrinking to microscopic size and destroying his intellect from within. "I'll just go to your brain and delete the knowlege of where you hid the master disk! And, as an added bonus, I might as well make your entire brain... [[BuffySpeak nn-not smart... no more]]."
** In "Plague of Babies" Zim does this ''successfully'' -- he fends off a horde of aliens who are fully sentient but visually similar to human infants by combining GIR with a power amplifier to create a lobotomizing wave that destroys their minds. He then returns them to their covers as real babies to random parents (where they had already been hiding as oddly unaging babies for 8-years). Yeah ''Invader Zim'' is kind of disturbing that way.
* ''WesternAnimation/RockyAndBullwinkle'' had Goof Gas in one arc. "One poof, you're a goof!" as Boris puts it. [[DisabilityImmunity Doesn't work on ]][[TheDitz Bullwinkle]], though.
-->'''Boris:''' No brain, no effect!
* In the ''WesternAnimation/LiloAndStitchTheSeries'' episode "Spike", Jumba reveals that one of his earlier experiments had quills that contained a venom which reduces anybody's intelligence to 1% of its original functionality. Strangely, it doesn't seem to affect him, but he later clarifies that it does, it's just that he's so smart that even 1% of his normal intelligence seems normal.
* ''WesternAnimation/SpongeBobSquarePants'': Mermaid Man and Barnacle Boy have the "Orb of Confusion", a literal IdiotBall which turns anyone in its range into a drooling idiot. Unfortunately, the range of the Orb is only a few feet, so it only affects the holders.
* ''Franchise/TheTransformers'': According to the production material at least, Wreck-Gar packs a ranged weapon that temporarily does this.
* In the ''WesternAnimation/SuperFriends'' episode "Around The World In 80 Riddles", The Riddler sprays Batman, Robin, Wonder Woman, and Superman with his "Stupid Spray", which slowly saps its victims of their intelligence. He then leads the heroes on a riddle and booby-trap filled chase around the world, stalling for time until the spray completely takes hold. At the end, the heroes become reduced to toddler-like intelligence, but manage to grab the antidote and defeat Riddler.
* On ''WesternAnimation/{{Doug}}'', Dr. Klotzenstien drained the brains of his fellow classmates to get the answers of a pop quiz correct. He tried to drain Quailman's, but ended up with a frog's.
* In ''WesternAnimation/RickAndMorty'', Mr. Needful gives Rick a microscope that lets him "see things beyond comprehension". Upon having it analyzed, he learns that its actual purpose is to make him mentally retarded and thus too stupid to understand anything.