Brain In a Jar

""We are all aware that the senses can be deceived, the eyes fooled. But how can we be sure our senses are not being deceived at any particular time, or even all the time? Might I just be a brain in a tank somewhere, tricked all my life into believing in the events of this world by some insane computer? And does my life gain or lose meaning based on my reaction to such solipsism?""

- Project PYRRHO, Specimen 46, Vat 7 (Subject termination advised), Sid Meiers Alpha Centauri

The Wonders of Science can keep a human brain alive in a plastic fishbowl with a few wires and doo-dads running into it. Sometimes this is benevolent, but usually it's nefarious. Occasionally, an underachiever Mad Scientist may need to keep the whole head alive, not just the brain. Sometimes the spinal cord and/or eyeballs are also there.

Sometimes it is presented as the end result of natural evolutionary processes. One day, we may find the rest of our bodies superfluous and exist simply as disembodied brains.

Occasionally with this trope, a virtual reality is put into the brain so that it thinks it's a regular person with a body, making it a sort of Lotus Eater Machine. See The Other Wiki's "brain in a vat" article for further discussion of this idea.

It seems that in about one in five examples of this trope the brain will always be Hitler's. Walt Disney (or, more likely a No Celebrities Were Harmed Expy of him) is also popular. Expect them to be given mobility by being encased in robotic life support units... with Death Rays! For Science!

Compare with People Jars and Man in The Machine; pretty much the same thing, but with complete bodies instead of just a brain. Compare also Soul Jar, in which the more immaterial essence of one's self, is preserved. Compare Heart Drive, for a robotic (and sometimes biological) equivalent. Compare with Oracular Head when the head may be preserved by other means and used for answering questions of a divinatory nature. Compare to Losing Your Head when the whole head is preserved and capable of independent movement. This may or may not lead to And I Must Scream.

Anime & Manga

 * The founders of the Time-Space Administration Bureau in Magical Girl Lyrical Nanoha Striker S turn out to have been reduced to these.
 * The Kedora from Mazinger Z and Great Mazinger. Ken Ishikawa one-shot "The Relic of Evil" revealed that  They would show up later in Shin Mazinger.
 * Most full cyborg models in Ghost in The Shell allow for the case that holds the brain to be removed and connected to an external life support system. In one episode of Stand Alone Complex a government official is about to be smugled out of country by hiding his brain in a suitcase.
 * Both the anime and manga versions have minor characters described as Jameson-type cyborgs which take this more literally than most. Most full body cyborgs have a body that at least looks human but Jameson-types eschew this with a roughly cubic metal box on wheeled legs with a camera on a stick and a manipulator arm. For extra irony the anime one runs a company that specialises in growing cloned organs for those who don't want cybernetic replacements if injured... and he got the money to found the company by selling all his organs in the first place.
 * Part of Araya's "Spiral Paradox" in Kara no Kyoukai relied on these.
 * The Magi computers in Neon Genesis Evangelion are powered by human brains.
 * Hard to say. The episode mentioned "organic supercomputers" that bear a strong resemblance to a human brain.
 * In Akira, this is
 * Lordgenome was brought back as this in Tengen Toppa Gurren Lagann to serve as a living computer and Mr. Exposition. Except, in his case, he's the entire Head In A Jar (the jar itself preventing this from being a case of Losing Your Head).
 * Dragonball Z's 2nd movie, World's Strongest, features Dr. Wheelo, who seems to be a brain in a jar. But then turns out to be a brain in a jar in a massive mecha. With guns. And lasers.
 * Despite being an Anime-version of a Western pulp series, Simon Wright from Captain Future should be mentioned here. He is an archetypical brain in a (highly mobie) jar, with tractor beam and other appendages.
 * It is (briefly) revealed in ROD the TV that
 * Elfen Lied: Oh god, Number 28 ...
 * In the Lupin III movie Secret of Mamo,
 * of To Aru Majutsu no Index has been reduced to this after Accelerator horribly dismembers him. It's also forced to create a constant stream of for the use of Academy City's soldiers.
 * In Bleach, Aaroniero Arrurerie's true form is that he has a glass jar where his head is supposed to be, filled with a blood-like substance and contains two Hollow-mask heads.

Card Games

 * A longtime Running Gag on Magic the Gathering's website is that Magic's Research And Development department is run by Gleemax, a literal Brainina Jar.
 * Which even has its own (not tournament-legal) card. The gag, by the way, dates back to at least the February 1998 issue of the long-defunct Duelist magazine, in which Mark Rosewater explains the 'Top Ten Myths About Magic R&D' -- the myth about Gleemax is listed as #1, and it's not quite clear from context whether MaRo refers to an actual earlier myth or is just throwing in a red herring on the fly.
 * Also, this card.
 * The Brain In A Jar is an enemy in Star Munchkin.
 * Lord Slogar, one of the characters in the card game Gloom is a brain in a jar.

Comic Books

 * The Two Thousand AD futuristic sports team The Harlem Heroes suffered a crash in their first adventure. One member became a brain in a jar as a result.
 * Another 2000 AD strip, Bad Company, featured Kano, a patched-together half-mad soldier who believes he carries the human part of his brain in a box.
 * Doom Patrol villain The Brain in The DCU. In one continuity he finally does manage to get a body--only to die in an explosion a few minutes later, moments before kissing his long-time boyfriend Mallah.
 * Who's a talking French Gorilla. You had a Brain in a jar in a robot being in love with a talking French Gorilla. Gotta love comics!
 * In the Marvel Universe, Invaders and Alpha Flight villain Brain Drain.
 * Also in the Marvel Universe, the Eternal Brain, a Golden Age hero later revamped as a member of the Retcon-riffic superhero team the First Line from the Marvel: The Lost Generation series.
 * Also in the Marvel Universe we have Marta Johannsen/No-Girl, a mutant kept alive as a brain in a jar to be used as a telepathic weapon before the X-Men rescued her.
 * The Kree Supreme Intelligence is a combination of their world's greatest minds, all in one big jar.
 * And Doctor Sun, a Chinese enemy of Dracula in Marvel Comics (We know he's Chinese because we are told).
 * One of Hellboy's enemies is Professor Doctor Herman Von Klempt, the Nazi head-in-a-jar.
 * More literally in the spinoff oneshot "The Iron Prometheus" starring Badass Normal Lobster Johnson. In order to extract the secrets of the Vril Energy Suit from Professor Gallaragas the villains literally do this to him.
 * Atomic Robo has the crazy scientist who isn't just a brain in a jar..
 * In Sonic the Hedgehog, Dimitri has become a head in a jar.
 * In Avengers: The Initiative, Think Tank is a member of Montana's state superteam, Freedom Force. To all appearances, his head is a brain in a spherical glass case perched atop an otherwise completely normal human body. He's telekinetic and wears a headband and not much else is known about him.
 * In the Elseworld Superman & Batman Generations, Lex Luthor is reduced to a brain in a jar . He gets a robot suit powered by Kryptonite, becoming this universe's version of Superman villain Metallo. In Generations 3, he causes even more trouble
 * President Rexall of Give Me Liberty becomes one of these after his coma. He even campaigns as such...
 * During an early 90's Superman story Lex Luthor fakes his suicide and has his brain (along with spine and eyeballs) put in a vat from which it directs its very own transplant to a younger Luthor clone.
 * In the story "Operation Friendship", in issue #41 of Tales from the Crypt, a genius who felt that he was losing his best friend to said friend's less-intellectual new wife removed about two-thirds of the guy's brain and kept it in a jar with a speaker attachment.

Fan Fic

 * in Calvin and Hobbes: The Series.

Film
""Legend has it when the smartest man in the world died, they put his brain in a jar. This is not that brain.""
 * The Brain that Wouldn't Die (Actually a head in a pan, but close enough)
 * Another head in a pan (with exposed brain yet!) in The Frozen Dead.
 * They Saved Hitlers Brain
 * The Brain From Planet Arous
 * Invaders From Mars
 * Donovan's Brain
 * Fiend Without a Face
 * The Atomic Brain
 * The Man With Two Brains
 * Mars Attacks!
 * In Young Frankenstein Igor was sent to retrieve the brilliant Hans Delbruck's brain from the Brain Depository. Igor drops the jar containing the scientist's brain, and instead takes a different jar marked "ABNORMAL - DO NOT USE". After the monster reveals its true nature, Dr. Frankenstein asks Igor whose brain he put in the body. "Abby someone." "Abby who?" "Abby Normal."
 * In the German-dubbed version, this became: "I took the brain of a cleric, an abbot (Abt)." - "What abbot?" - "Abt Normal." By the way, as he mentions on the DVD, Mel Brooks had Froderick Fronkensteen Frederick Frankenstein send Igor to fetch Hans Delbruck's brain because that would rhyme with "Mel Brooks' brain". So it is not a reference to the German politician and historian Hans Delbrück (1848-1929), father of the Nobel Prize-winning German-American biophysicist Max Delbrück (1906-1981).
 * Robo Cop 2 (even after it's put inside the titular robot).
 * Apparently the original Robocop is also a brain-in-a-jar-in-a-robot, with only the face being additionally transplanted into the robotic head. And even that is debatable (R3 states that it's the original face, while the original script contained a removed scene where Murphy's "terminator-like" skull would be shown).
 * And let's not forget Cain whose brain is about to be transferred into a robot as well. His brain is LITERALLY in a jar with his Eyes STILL ATTACHED. He, also, sees his FACE that's been cut off of his head.
 * Uncle Irvin in The City of Lost Children
 * X-Files: 
 * in Crank 2: High Voltage.
 * Brain from Igor, though he has wheels and a robot hand so he can move around.


 * One of the characters in Run Ronnie Run ends up this way.
 * Grievous from Star Wars, who is actually reduced to a brain inside a fully robotic body.
 * Also, the monks in Jabba the Hutt's temple-turned-hideout.
 * The uncle of the two murderous cannibals masquerading as vegetarian chefs in the weird horror-comedy Blood Diner is reduced to one of these (complete with eyeballs). He still orders them around to put together a body for some evil goddess out of all the girls they've killed. We said this was a weird film.
 * One of the characters in Tammy and the T-Rex ends up as a brain in a pan.

Literature

 * The Conjoiners in Alastair Reynolds's Revelation Space series tend to opt for a brain-in-jar form of treatment when they're very old. However, their "jars" are mobile, crab like devices. The Demarchists also use this for their outer system police; a pilot joins up, his brain and spinal cord is removed and inserted into a small space craft, with a remote controlled drone for them to use when inspecting ships. When they're done with their term, their brain is inserted back into their body.
 * Mayflies by Kevin O'Donnell
 * Plus by Joseph McElroy
 * William and Mary by Roald Dahl. Cold and dominating husband William is dying of cancer, but has his brain and one of his eyes kept alive. It's presumed that his wife, Mary will torment him by doing all the things he forbade her in front of him, now that he's helpless.
 * A TV version of this short story explicitly shows her doing just this.
 * The Whisperer in Darkness (1930) by HP Lovecraft is the Trope Codifier, in which the alien Mi-Go plant living human brains in cylinders to transport them to other planets, which the human body apparently cannot withstand.
 * That Hideous Strength by C.S. Lewis. A whole head this time, with an overgrown brain, plus air tubes to pass "breath" through the vocal cords and mouth allowing it to speak. And artificial drool.
 * Though it's later revealed that the Head isn't really alive in its own right.
 * A Wrinkle in Time, by Madeleine L Engle, in which an oversized brain referred to as IT has gained complete telepathic control of an entire planet. IT runs the planet on a heartbeat which controls the life of everyone. Despite being in a novel, so great is the influence of IT that the characters know how to capitalize the name.
 * The Star Wars Expanded Universe, specifically the short story anthology Tales From Jabbas Palace, reveals that the spiderlike droids seen in Jabba's palace in Return of the Jedi are mechanisms used for getting around by a group of monks who have chosen life as brains-in-jars. (You can actually see the jars on the undersides in the film if you know to look for them.)
 * Bib Fortuna, when a fellow Twi'lek and associate of his was slated to be fed to the Rancor, had the man's brain removed and stuck in one of the spider droids, leaving the brainstem in so that the body would still spasm appropriately. Nat Secura did not appreciate this, and Bib believed that without a body Nat was going insane. The epilogue of that anthology reveals that and a number of the other characters who didn't get out eventually joined him. The X-Wing comics reveal that   was still able to plot and get messages out; eventually yet another Twi'lek came to look for Jabba's treasures and carry   off, making him use computer skills in some gambit against Rogue Squadron, heaping a lot of verbal abuse and using electric torture on the brain walker in the process. The gambit failed, naturally, and the other Twi'lek tried to ditch the walker and head back to Tatooine alone. But   stowed away and, after the other Twi'lek was stabbed, managed to drag him back to the palace and the monks. Cut to the Twi'lek rising out of a bacta tank, and the attendant droid remarking on the loyalty of the brain droid, how it had insisted on having a restraining bolt fitted to it, and that the scars on the Twi'lek's head seemed to indicate a brain transfer. Devious,  . For someone with a "weak will", that's rather Magnificent.
 * Part of a Twi'lek's brain is in his or her headtails, so a Twi'lek brain in a jar looks rather odd.
 * Also in Star Wars Expanded Universe: In the Tales of the Jedi series, a Jedi Master by the name of Ooroo is a brain-like, methane-breathing alien who must stay in his fishbowl as oxygen is lethal to him. His species, the Celegians, was given a name and some background for RPG; authors never saw a great use for them.
 * The prequels of Dune have brainjar villains riding around in giant war machines (just because they can), who cause the Butlerian Jihad through poor programming of their computerized inside "man" and wind up as minions/slaves themselves. Besides the Titans (giant war machines ), are the Cogitors, humans who gave up their bodies to spend millennia contemplating the mysteries of the universe. As a group they have declared themselves neutral in the war where humanity is being exterminated like rats.
 * The novel Donovan's Brain by Curt Siodmak.
 * Larry Niven's short story "Becalmed In Hell" has a sans corpus fellow running a probe to the surface of Venus, and contains a Shout Out to the above book by naming the bodiless chap Donovan.
 * The first novel based on the Doom videogames had the Legions of Hell actually Handwaved as genetically engineered scare-tactic bioweapons created by aliens who consist of huge brains in Giant Spider-like mobile carriers.
 * Neil R. Jones is credited with inventing this trope in 1931, making it Older Than Television.
 * In Harry Potter, the gang runs into a room with several flying brains in jars while fighting their way through the Hall of Mysteries. Ron (who's punch drunk at the time) starts playing with them and they begin to attack everyone...with tentacles made of thoughts. The Department of Mysteries is a very strange place.
 * Orson Scott Card's Wyrms features talking disembodied heads kept alive by some kind of leech.
 * Occasionally seen in the Perry Rhodan universe, with both disembodied human brains (though usually those are given robot bodies at the very least) and alien ones -- the 'Central Plasma' that governs the mostly-robotic Posbi species is basically one giant protoplasmic brain in a jar. One arc of the series even dealt with the abduction of the titular protagonist's brain into a distant galaxy; an android brain was substituted and operated his body for nefarious purposes while he tried to find his way back. (Good thing the civilizations of said galaxy had their own brain transplant technology as part of their quest to extend life, even if it did contribute to their acute overpopulation issues; so, plenty of disembodied donor brains around there, too.)
 * Nightwings by Robert Silverberg. Brain jars effectivly serve as information storage systems.
 * The Takeshi Kovacs series by Richard K. Morgan features another twist on the cyberbrain sub-variant of this trope, in the form of "cortical stacks" implanted in every person's brain that basically serve as a mirror backup of the brain in question. Stacks can be transferred to other bodies ("sleeves") at will, transmitted across networks, mounted within VR constructs or simply stored to disk.
 * Keith Laumer's A Plague of Demons, in which human brains are installed in alien war machines.
 * Daniel Dennett's short story "Where am I" about a man being separated from his brain, which explores relevant philosophical ideas.
 * Orson Scott Card once jokingly referred to this as a possible solution to Bean's condition. He also expressed serious revulsion at the idea, so we probably don't have to worry about him following through with it.
 * (Edmond Hamiton / Mort Weisinger / Oscar J. Friend)'s Simmon Wright of the Captain Future universe almost is an archetypical brain in a jar.
 * E. C. Tubb's Dumarest of Terra series have the evil Cyclan led by an interconnected set of ancient brains in jars.
 * The space-faring slavers from Vernor Vinge's Tatja Grimm's World kidnap people, remove their brains and then fit them to a computer that suppresses their personality without totally trashing their intellect. The result has computer speed and power with some human intuition and intelligence, forming a useful Wetware CPU.
 * Left Brain, who replaces Eddie the Heart of Gold computer in And Another Thing, is actually, put in a jar and connected to the ship.
 * An Igor in Making Money cites the invention of a "living brain extractor" as proof of a famous scientist's great achievements. Also as proof the inventor was not mad, but what else can be expected of an Igor?
 * In the Deathstalker universe there exist psi-blockers, devices that espers using their powers in a given area. It is eventually revealed that Empress Lionstone had them created by extracting the brains from espers and sealing them in containers. The psychic screams of agony were what prevented espers using their abilities.
 * The later series replaced the original psi-blockers with genetically-cloned esper brains that could generate the same effects without the horror.
 * Ypsilon/Duktig in P.C. Jersilds En Levande Själ, who had the rest of his body amputated and his memory wiped.

Live-Action TV

 * Star Trek the Original Series: "The Gamesters of Triskelion", "Spock's Brain"
 * Doctor Who: The Keys of Marinus and The Brain of Morbius.
 * And Lady Cassandra in The End of the World and New Earth.
 * The Outer Limits: "The Brain of Colonel Barham"
 * Way Out and Tales of the Unexpected: "William and Mary"
 * Bionic Woman: The 1970s version had one brain in jar villain with floating eyeballs and telekinesis.
 * This happens to Lister's "future self" (one of them, anyway) in Red Dwarf
 * Lister also mentioned in an early episode that his uncle's brain was in a jar and that it was really sad, as he wasn't dead yet.
 * "Mr. Newman" of the short-lived series Now and Again spent some time as a brain in a jar after getting hit by a train but before getting his new Super Soldier body.
 * Lexx. Slightly subverted in that the brains of the former His Divine Shadows somehow don't need jars in order to survive.
 * They may be sustained with protoblood. Though given how easily they're destroyed, maybe not - protoblood would make them invulnerable. Possibly a weaker derivative. Or maybe having housed the essence of His Divine Shadow makes them this tough as a side effect.
 * In Mystery Science Theater 3000, Brain Guy had his brain in a dish...that his body was carrying. He claimed that his species had evolved beyond the need for a body, despite the obvious helplessness of the exposed organ without a body to carry it around. Several skit gags involved separating his brain from its body or adulterating the brain dish with Mountain Dew or similar to get a funny reaction.
 * In the Wizard of Oz pastiche Tin Man, the brain in a jar turned out to be the brain of the Scarecrow counterpart, used to construct and power a Doomsday Device.
 * It's not a brain, but according to The Colbert Report, doctors can now keep a pair of lungs alive and breathing in a glass dome. Creepy!
 * The brain of Saint Peter shows up in the DAAS Kapital episode "Felicity", and is promptly corrupted by the All Stars.

Music

 * Country music singer James Bonamy had a song called "Brain in a Jar".
 * One of the tabloid headlines mentioned in "Midnight Star" by Weird Al Yankovic is "They're keeping Hitler's brain alive in a jar".
 * In the song "Lovecraft in Brooklyn" by The Mountain Goats, beings from beyond the stars are coming to put her our brains in mason jars.

New Media

 * This set of emails between a 419 scammer and a wise guy.
 * The late Usenet personality Gharlane of Eddore always depicted himself as being a brain in a jar.
 * According to Marshall Brain, we'll likely all choose to be this way in a few decades.

Newspaper Comics

 * Several Far Side cartoons played with this trope, including one where a Jan in the Pan-esque severed head begins screaming in horror at its circumstances, only to receive a anti-insanity slap from the mad scientist who created it. "Thanks, Professor, I needed that."
 * An ongoing story in Tom the Dancing Bug features the life of a disembodied brain in a vat. The brain's owner keeps it on his desk as a conversation piece, and uses his desktop computer to feed it simulated sense data that leads it to believe it is an ordinary human living out a humdrum existence in the real world.

Tabletop Games

 * Dungeons and Dragons has the Mind Flayers, the Illithid race, their leaders are Elder Brains. Gigantic Brains in Jars. With Psionic powers.
 * Various undead supplements have provided more normal-sized brains in jars, like here for example.
 * A brain in a jar, salvaged alive from an accident victim by Ravenloft's Dr. Frankenstein Expy, is a mind-controlling criminal mastermind in Dementlieu.
 * Mutants and Masterminds had one as a sample villain.
 * Second edition had it as a potential villain archetype. First edition, using the META-4 universe, had the Atomic Brain who was a former Manhattan Project researcher whose brain survived the explosion of an experiment. A combination of resentment at Oppenheimer taking credit for the atomic bomb and frustration over a lack of limbs led to the Atomic Brain becoming a supervillain.
 * A tiny bit of an aversion, however, in that the Atomic Brain's... brain... floated above his robotic body.
 * GURPS has a disadvantage called "No Physical Body" which turns you into this. You're immobile and anybody who interacts with you is likely to recoil in horror. So it kinda sucks, except that it gives you a ton of character points you can spend on magic/psionic powers or other mental abilities.
 * Shadowrun
 * Supplement Threats 2, section "Halberstam's Babies". The evil scientist Dr. Halberstam continues his experiments by extracting the brains of children and storing them in containers, then connecting them to the Matrix and training them to be super deckers.
 * Supplement Aztlan.
 * Thomas Roxborough, a major shareholder in Aztecnology, is currently a mass of undifferentiated protoplasm (including his brain). Sort of a "cancer in a jar".
 * Aztechnology is rumored to be working on biocomputers - computers based on human brains floating in a vat of electrolytes.
 * Also how full cyborg conversion works.
 * Full-conversion Cyborgs in Rifts are basically brains and a few vital organs wired into a robotic body.
 * Star Frontiers module SF1 Volturnus, Planet of Mystery. The slavebots in the Sathar Artifact are controlled by a Sathar's brain which is in a large fluid-filled flask. The flask is connected to a radio with wires.
 * Gamma World. Borgs, Permanent Cybernetic Installations and Think Tanks in 1st Edition. Borgs in 2nd Edition.

Videogames

 * In the Metroid video game series, Mother Brain, a re-occurring final boss, is just a brain in a tank, guarded by various gun turrets and organic barriers. It is supposedly a biological supercomputer.
 * In Super Metroid, once it is defeated,.
 * Metroid Prime 3: Corruption features the Aurora Units, which are also brain-like organic supercomputers in large tanks. There's even been some theories on how they may be related to Mother Brain in some way, fueled by the very large number of Mother Brain references made both in-game and in supplementary material but never fully elaborated upon as far as direct connections go.
 * The security robot B.O.X. in Metroid Fusion contains a brain in its cybermechanical spider-like body. The fact that it has a nonmechanical brain doesn't seem to have any specific practical applications as far as robotics goes. However, it serves as a justification for the robot fighting Samus: a semiorganic robot being infected by the X-Parasites makes more sense than some random security robot that spontaneously goes rogue in the midst of a hostile takeover by an alien virus.
 * Though it was simply rogue when it first attacks you. It's when you break the "jar" that the X-parasite can infect it.
 * The Clockwork King in City of Heroes is a Brainina Jar mounted on a mechanical frame he operates telekinetically.
 * The Clinical Immortality secret project from Sid Meiers Alpha Centauri. Though this technically included the spinal column
 * ... and eyes. The movie gets its Nightmare Fuel from the eyes just staring at you.
 * The Bioenhancement Center facility, when constructed, gives you the page quote.
 * In Fallout Tactics, Vault 0 is run by the Calculator  In order to win the game  . Depending on what kind of game you played, or if you take up the offer, or if you just refuse it and let the counter run down, the game ending changes.
 * Not to mention Skynet from Fallout 2. Although he's technically an AI that wants to conquer the world, you bring him out into the world through a cybernetic brain inside a Brain Bot. You can also end up bringing a Chimp or normal human brain instead, but that isn't quite as good.
 * Or you can use an abnormal brain, which will render him The Load, too stupid to do anything but carry items (including comprehending that it's been fired). The only way to get this version of Skynet out of your party (thus making room for someone actually useful) is to kill it.
 * Fallout 3
 * Also across all Fallout games is the Robobrain, a robot that has an organic brain as a CPU - notable in the fact that none of the brain's original thoughts are present (it is said that the brains used range from Chimpanzees to Humans).
 * In Fallout New Vegas DLC Old World Blues, there's the Think Tanks, who are a group of Pre-War Mad Scientists who put their brains in floating robots with monitors for eyes and mouthes.
 * This also happens to the Player Character in this DLC as well. When you first arrive at the Think Tank your brain is extracted and replaced with cybernetic parts intended to allow your body to continue to function for simple slave labor. Somehow, as a result of a combination of an old head wound and a freak scientific accident, you retain coherent thought, even though your brain is elsewhere, allowing your "mind" to be in two places at once, with your brain being treated as a seperate entity. Yeah Old World Blues is weird.
 * There's also the K9000, a minigun powered by the brain of a dog. It'll even bark, whine and growl and includes cybernetic ears and noses.
 * Kingdom of Loathing allows you to fight the Brainsweeper, a Brain In A Jar that is powering a set of brooms. (For Science!) It Randomly Drops a Disembodied Brain in a jar, which you can use to Frankenstein together a chef, bartender, maid, or a few other things.
 * In Brain Dead 13, the Mad Scientist villain is one of these.
 * The Bio-Drones of X-COM: Terror from the Deep, only their jars can hover anywhere it wants, are hard to hit, can take quite a bit of damage, come equipped with highly accurate weapons, and explode with a huge radius upon death. Oh, and if you research them, you find out that some of them are human brains that have been butchered to obedience by the aliens.
 * Doctor Brackman of Supreme Commander made himself into a brain in a jar to stay alive after his nominal death. One thousand years of constant warfare later, and he's still going strong as the leader and father of the Cybran Nation.
 * In No More Heroes, the #5 ranked Letz Shake controls what looks like a Super Collider powered by a brain in a jar.
 * In Desperate Struggle,
 * Some of the fans think that
 * Psychonauts. Later in the game,
 * Several enemies in the Quake series, notably the Parasites, the Flyers, and the Technicians, the latter who is a literal brain-in-a-jar controlling a flying-saucer-like machine.
 * In Red Alert 2, Yuri keeps several brains in jars to research psychic technology. And in the expansion there is a very literal think tank...
 * The protagonist of Dead Head Fred is killed and reanimated in this form at the beginning of the game, though he is at least attached to his original body. His... Predicament lets him switch his head with other things, each with their own gameplay uses.
 * F-Zero has Deathborn. It's the only part of his body still remaining after being reconstructed 3 times.That includes his Soul.
 * The Sims: Busting Out had a brain in a jar as furniture. In fact, said furniture is involved in one of the challenges.
 * Streets of Rage 3 has the recurring villain, Mr. X, show up as a brain in a tube. He still wishes to rule the city.
 * The Bio Derm (artificially cloned/grown human pilot) "Mentor" in  MissionForce: Cyberstorm  is one of these, an experiment meant to test the feasibility of direct neural link to a HERC. It works - Mentor is scarily competent - but the tradeoff is a very short lifespan.
 * Red Falcon can be reduced to this in Contra III: The Alien Wars. Of course, being a disembodied, floating brain only makes him deadlier, as he can then use a variety of psychic weapons and (in Hard mode) a metallic, armored sheath with octopus-like tentacles.
 * Shin Megami Tensei's interpretation of Omoikane, Shinto goddess of wisdom and intelligence, depicts "her" as a disembodied brain with eyes and several dozen feelers.
 * A brain in a jar is the whole point of the game Cortex Command. Sometimes, it's hanging in a bunker, and sometimes it's on a robotic exoskeleton and can move, though it's fragile and if it dies, you fail.
 * The second Freedom Force game has 'Eyes of the Reich', which are (you guessed it) Nazi Brains in Jars with Frickin Laser Beams.
 * Joe Musashi from the Shinobi games had to deal with B.I.A.Js quite a few times in his missions. In Revenge of Shinobi a stage taking place aboard a huge military transport ended with a Boss Battle against a Brain in a Jar that actually controlled the transport. In Shinobi 3 one of the missions takes place in a biowarfare lab where he would deal with Brains that broke out of their jars, Brains with Wings, and at the end, a Brain in a Dalek-esque battle machine.
 * Ghost Master features a ghost of a brain in a jar.
 * In House of the Dead: Overkill, this is the final fate of.
 * Pun-based example: An Animaniacs spin-off game for PC has this as a final boss: The Brain mounted in a jar and controlling 'the Think Tank!'. Notably, this wasn't his idea.
 * The Mission:Impossible NES game. The second-to-last room in the Very Definitely Final Dungeon has its walls lined with brains and hearts in life-support tanks. It's even scarier when you realize how much effort it took to get there, and that nothing else in the game hints that the Sinister 7 were creating bio-weapons.
 * The Big Bad of Gotcha Force, the Galactic Emperor. Not so much a "in a jar" as "in an energy field"... mounted on
 * The Big Bad of Space Station Silicon Valley turns out to be a Brainina Jar called... the Evil Brain. It taunts EVO while spraying the Earth with the Doomsday-O-Matic Shrinky Ray, but is easily destroyed with EVO's laser. However,
 * In episode one of Sam and Max Freelance Police: The Devil's Playhouse, "The Penal Zone", Sam and Max encounter a disembodied alien brain named Gordon on General Skun-ka'pe's ship. As suggested by the title of episode three, "They Stole Max's Brain!", Max ends up spending some time as one of these.
 * The Deadly Brain in Oni.
 * Lifeline/Operator's Side:, has become this. His brain was recovered and was being used to
 * Tampo, the first boss of Stinkoman 20 X 6, is first seen as a mechanized Brain in a Jar that was destroyed by Stinkoman prior to the game's first level. The level ends with Tampo's brain coming back to get Stinkoman for revenge.
 * One of the bosses of Metal Slug 6 is a humongous brain with eyeballs in a jar... on top of an equally huge alien mecha. It's one of the hardest boss fights in the game.
 * These appear as enemies in Earth Bound Zero.

Web Comics
"Alien: You just ate the left side of our brain, the one that handles all logic. I'm the abstract right side! I think I'll go paint my emotions now! Oooh! Something shiny!"
 * Schlock Mercenary: Just about all' of the original Toughs (except Schlock) end up as jarred heads (pun intended) after the 2001 Schlocktoberfest storyline. This gives the frequently disembodied Der Trihs a sense of deja vu''.
 * Moreover, that anyone injured badly enough would end up with their head in a jar and with a few punchlines at their expense (usually by Ennesby, embittered over not having a body in the first place) was a running theme, especially earlier in the comic's run.
 * In Narbonic, the Alternate Future version of is a brain in a large vat.
 * in the spin-off Skin Horse is one of these as well.
 * Adolf Hitler is a brain in a jar in the LEGO photocomic Irregular Webcomic.
 * At one point he builds a supercomputer out of a bunch of cloned Hitler jar-brains wired together.
 * Dr. Haynus in Evil, Inc. is a brain in a jar attached to his ex-wife's dog (the dog retains control of the body).
 * A Brainina Jar alien makes an appearance in this Sluggy Freelance strip, with the added twist that the creature's brain is divided into a right and left side, each in separate jars.


 * In Homestuck, Dave comes across the alchemy combination that makes Dave's Brain In A Jar during his experiments with Item Crafting. It's too expensive for him to make because the organ is virtually inimitable, but he uses the code in alchemy to make the SBAHJifier camera.
 * In this Order of the Stick strip, Xykon references Brain in a Jar transformations as a method to avoid death. Though he makes it clear that he wouldn't become one unless he had to.
 * In Minion Comics, Hitler's head is seen in a jar attached to a giant rampaging gorilla.

Web Originals

 * Robotman, one of the Denver Defenders, is essentially a Brainina Jar where the jar is a powerful robot body.
 * The Batteries in The Mercury Men are brains in jars.

Western Animation
"Beast Boy: Hey, check it out! [flash-freezes The Brain] Brain Freeze!
 * The Dexters Laboratory Made for TV Movie "Ego Trip" has Mandark turned into a brain in a jar following his defeat by 4 Dexters from different ages... and Dee Dee's intervention.
 * Hector Con Carne's Brain in Evil Con Carne. Variation in that his stomach also is in a jar... and developed its own sentience.
 * Futurama had the heads of various 19th-21st century personalities preserved in jars, including Richard Nixon, who eventually became president again. Used more for comedy and satire than creepiness. It was never explained exactly how, say, George Washington's head could have been preserved in the first place. Also, the main antagonists of several episodes are flying brains outside of their jars.
 * Done to an extent in "How Hermes Requisitioned His Groove Back", where Bender's personality and intelligence are downloaded into a floppy disk.
 * Inverted with Earth President Nixon's vice president, Spiro T. Agnew, who is a headless body.
 * They eventually Handwaved the process as being a form of limited time travel; by incorporating some kind of powdered opal into the fluid heads are kept in, they create a tiny bubble in which the heads are perpetually in the time period during which they were alive. Presumably a certain amount of cloning is involved for certain heads as well.
 * After starting out as a human, Baxter Stockman eventually becomes one of these in the second Teenage Mutant Ninja Turtles series. The Shredder, of all villains, quips that "You should have quit while you were a head." Also, in the Fast Forward episode "The Journal", the turtles read about future events in their lives, including Donatello being reduced to a brain in a jar...with a mask on.
 * The Fairly Odd Parents: In "Future Lost", the evil brain that aspired to take over had a strange weakness - put juice pills in its tank, and it would get a Brain Freeze.
 * Not just that. They also dumped some ice into it, making a giant slushie.
 * Also, every Yugopotamian has their brain clearly visable in a glass dome on their heads.
 * Team Galaxy: "Brett's Brain"
 * In Buzz Lightyear of Star Command, while the Star Command employs the Little Green Men seen in Toy Story, Zurg's minions are brains in jars (who frequently mention this situation when the boss complains).
 * The GoBots in Challenge of the Go Bots are brains in cyborg bodies.
 * Mok's supercomputer in Rock and Rule looks like one of these, although not quite as easy on the eyes.
 * Mr. Burns in The Simpsons ends up as one of these, attached to a robot body (but still fond of his teddy bear.)
 * The Brain from the Doom Patrol comics as listed above appears as the Big Bad in the last season of the Teen Titans animated series. Beast Boy was able to make an Incredibly Lame Pun on The Brain's defeat:

[everyone present groans]"

"Zozo: That's Commander Negata?!
 * The Brain has also appeared on Batman the Brave And The Bold, voiced by Dee Bradley Baker, and Young Justice, voiced by Corey Burton (spouting Gratuitous French in both incarnations).
 * Tactical Commander Owen Negata from Adventures of the Galaxy Rangers. A BETA research scientist and tactician, he was killed in the Supertrooper Riot (though we don't learn this until later). What was left of him can fit into a little jar attached to a 1.5 meter by one meter repulsorlift platform. Zozo is rather shocked by it.

Waldo: His brain unit. His body died years ago."


 * An episode of Jimmy Two-Shoes had Jimmy and Beezy accidently knocking the brain out of their favorite soccer player's head. By the end of the episode, Beezy still hasn't given it back, keeping it in a jar among his memorabelia.
 * The Yolkians from the Pilot Movie of The Adventures of Jimmy Neutron Boy Genius, although they're technically egg yolks in glass egg-shaped capsules.

Other

 * Parodied by this shirt.
 * Animats or Cultured Neuronal Networks are almost a Real Life version of this trope, almost being that they aren't complete brains (and usually animal neurons).
 * According to Pat R's series of articles on the Final Fantasy series, when an intern suggested the Job System during the development of Final Fantasy III, Hironobu Sakaguchi (the creator of the series) responded by pausing blankly, heaping rewards on him, then chloroforming him and putting his brain in a jar so that Squaresoft would never be without his genius. The article goes on to describe some of the brain's other accomplishments, before its tragic downfall at the hands of the designer of Final Fantasy II.

Real Life

 * Averted by Mary Roach, author of Stiff, a nonfiction book about cadavers. Investigating the possible fates which await deceased human bodies, Roach considered donating her own to Harvard's medical school, in hopes of becoming a brain in a jar. To her disappointment, she learned that human brains preserved there for medical and scientific research are kept in plastic food containers, which hardly seemed worth it.
 * According to the Boltzmann brain hypothesis, it is far more likely for you to be a brain floating in space that believes it is in a large universe than for you to actually be in a large universe. And you'd never be able to find out. Think about it.
 * Dr Robert White's experiments with dogs, rats and monkeys: http://en.wikipedia.org/wiki/Robert_J._White