Who Even Needs a Brain?

"Dr. Cockroach Ph.D.: [about B.O.B] Forgive him, but as you can see, he has no brain.

B.O.B.: Turns out, you don't need one."

- Monsters vs. Aliens (B.O.B. then forgets how to breathe.)

In real life having your brain physically removed from your body pretty much means you are dead. In comedy however the results can be a little different, leading to one of three outcomes (besides the realistic fatal one that is):

Type I - Walking Vegetable: In this case the body is in a drooling zombie like state, able to walk after a fashion but otherwise almost totally unaware of anything going on around them. Any speech will be monosyllabic.

Type II - Stupid but Aware: In this case the character has simply turned into The Ditz - they are much stupider than usual but able to talk properly, walk around without bumping into things and so on. Probably the least common category.

Type III - No Change: This is most likely to happen to a character who is already The Ditz (or worse). Brain falls out, is stolen or whatever and the de-brained character acts exactly the same (and may not even notice their brain is gone.) Sometimes the brain will be far smaller than normal to begin with.

Not to be confused with Brainless Beauty (though of course this trope could happen to a Brainless Beauty.)

See also In One Ear, Out the Other.

Live-Action TV
"Kill counter: That makes 4, 997
 * Rare 'serious' example: the infamous Star Trek the Original Series episode "Spock's Brain." Spock's brain is stolen by aliens who use it as a computer to run their planet's infrastructure. For some reason, his autonomic functions still work, but he is completely unconscious. Kirk has to get the brain back quickly, because Spock's Vulcan physiology is especially dependent on that tremendous brain. (While a brain-dead human could be kept "alive" easily for quite some time) So that they can restore the brain quickly when they find it, McCoy rigs up a device that fits on Spock's head and allows his lifeless body to walk around, manipulated by a remote control. With three buttons.
 * SPOCK has made a song called "Mr. Spock's Brain", based on the above episode.
 * Borderline Type I/Type II case: In a Wizards of Waverly Place episode Alex and Harper switch brains and while trying to get back into each others bodies both brains end up in Alex's head. Harper's brainless body wanders around with a stupid grin on her face spouting random words though she seems to be slightly aware of the world around her in same way a baby is aware.
 * In a Horrible Histories sketch, there was this exchange:

Roman general: Make that 98.

Kill counter: Yeah, I'll give you that one. He's still moving, but realistically, he's not going anywhere without his head."

Video Games

 * In Illbleed, Randy's brain being removed turns him into a type 1. If the player fails to recover his brain, they can use "Brainless Randy" as a player character in later chapters... where other characters will converse with him as though things are totally normal, even though all he can do is make incoherent groaning noises.
 * In the videogame Psychonauts when the villain makes the campers sneeze their brains out, they end up as mindless zombies only able to moan "Teeeee-Veeeeee...." and stumble to the nearest set to start watching. If Raz can find the jars holding the brains, he can return the campers to normal with no ill effects.

Web Comics

 * Yeagar from Nodwick had his brain removed at least twice (once by an Illithid and once by an Evil Henchman). In the second case, Piffany drafted a nearby butterfly and put it in his cranial cavity. This, somehow, allowed Yeagar to stay mobile.

Western Animation

 * Oblina of Aaahh Real Monsters once sneezed her own brains out, leaving her body a drooling and mindless but mobile vegetable.
 * In one Ren and Stimpy episode, Stimpy takes out Ren's brain and replaces it with a telephone, leaving him a drooling vegetable. The brain, on the other hand, gets up and goes to work as if nothing has happened.
 * At the end of of one episode of Invader Zim, Zim sends a warning to himself back in time, but it has to replace something and that something turned out to be his brain. Rather than keel over, he just kind of sat there, drooled, and moaned a bit.
 * This is somewhat justified, as one (unaired) episode established that the Irken's (Zim's race) PAK (backpack-looking thing) is the actual "brain" of the organism, the body serving as something to carry the PAK around (though this does bring up the question of why there even is a brain). Another episode, Dark Harvest, plays this trope straight. Zim, in pursuit of human organs to improve his human disguise, replaces a secretary's brain with a can of soda. Nothing happens immediately, but when the phone rings, she holds it up to her face and foams out the mouth.
 * In the MIB cartoon series, Zed had his brain stolen. The procedure left his brain remotely controlling his body, manifested by him continually walking straight. The other agents blamed it on the thief's sick sense of humor.
 * SpongeBob SquarePants tends to use this type. On the multiple occasions where a character's brain gets removed, they tend to stand around and drool until it is replaced. In Patrick's case, this is often indistinguishable from his normal behavior.
 * This happens to Fanboy from Fanboy and Chum Chum in the episode "Brain Drain". His brain is evidently not subject to the laws of gravity, because it stays in mid-air while he is falling.
 * In the Futurama episode: "How Hermes Requisitioned His Groove Back", when Bender loses his brain (in disc form), all Bender can say is "I AM BENDER. PLEASE INSERT GIRDER." He still walks around but doesn't pay attention to where he's going in the slightest.
 * Although thats more a case of him losing his personality and resetting back to default.
 * In the Rocko's Modern Life episode "Boob Tubed" Heffer has his brain sucked out through the tv after sitting too close, he is reduced to a drooling idiot who spouts nonsense and thinks he can fly.

Real Life

 * Nicholas Coke would be considered a partial Reality Is Unrealistic for this trope, considering that his condition, Anencephaly, makes it so that he has no brain, only a brain stem. Against all odds he has recently turned one (babies born with the condition usually die within hours or days). You can regard this as a miracle as the family thinks it is or a Fate Worse Than Death as the baby apparently can't see, hear, suck, crawl, or sit up (or perhaps even think).
 * Shufflebrain, a series of experiments involving salamanders, had animals with their brains removed who remained alive yet stupefied. Replacing the brain in various positions resulted in Type III salamanders.

Film - Animated

 * B. O. B. from Monsters vs. Aliens as shown by the page quote.

Live-Action TV

 * In an episode of Sabrina the Teenage Witch Sabrina is infected by a Stupidity Virus, which leaves her literally empty headed and a shallow boy- and shopping-obsessed Brainless Beauty in personality.
 * There actually is a parasite that eats brains, but it's protozoan, not viral.
 * In a Show Within a Show Type II example one episode of the Saved by the Bell had the gang make a film about evil aliens invading. A history teacher (played by Jessie) had her brain sucked out her ear (via a straw) by an alien (played by Screech) while telling her class that "the Gettysburg Address was delivered by [brains sucked out]... Pee-wee Herman."
 * A Bit of Fry and Laurie has a textbook Type II.

Radio
"Doctor Frankenstein: When I created you, I neglected to give you a brain.
 * Radio: I'm Sorry Ill Read That Again once had a Frankenstein parody that included something like:

Monster (Lady Constance): Oh, I can't think why."

Web Comics

 * Quilt in Dominic Deegan is an Artificial Human (specifically a Flesh Golem) with no brain. He is fully capable of speaking, acting, and thinking, but he's an utter Cloudcuckoolander. He is, however, immune to brainwashing - "No brain to wash!"

Western Animation

 * Peri of Spliced ended up in a state somewhere between Types I and II: he was mostly incapacitated but could sorta walk around and mumble/scream for the return of his brain. When he found is brain had been implanted into a toaster (roll with it) he tried to shove it back in, toaster and all. I didn't work.
 * Meatwad of the Aqua Teen Hunger Force, a literal living wad of meat, does have a brain, but it's just a rubber toy with a jingle bell inside. He was given it apparently because he felt deprived with no brain. When it's removed, he still becomes less intelligent, but this seems to be a psychosomatic effect.

Real Life

 * In 1848, Phineas Gage had a pole jammed through his head that removed part of his brain. It didn't kill him, but he is said to have become much more cranky and dishonest after the pole went through his head.

Comic Books

 * Rare dramatic (well...) example: New Batman villainess "The Absence" has an enormous hole in her forehead and extending all the way through, with no visible brain, yet functions just fine, and may be smarter than before the hole happened. It appears to be a combination of a freak medical condition (which resulted in the brain lining the skull rather than sitting in the middle of it, meaning the through-and-through was more of a lobotomy) and Gotham City's water supply being seriously tainted.
 * In I Feel Sick, Devi reminisces about a particularly bad date she went on. A mongoose ate her date's brain, but he was so stupid to begin with that it took her a while to notice.

Film - Live-Action

 * In Addams Family Values Gomez and Fester are cheerfully reminiscing about all the (violent) pranks they pulled on each other as kids. Fester casually mentions that one time he waited til Gomez was asleep, then opened his his head and removed his brains. Gomez is surprised and sort of impressed by this revelation.
 * Hard to say what category Eddie from The Rocky Horror Picture Show falls under as we are only given hints of his behavior prior to having half his brain removed. (We know he had a criminal record and thought "head" was spelled "hed".) He still knew how to operate a motorcycle, but tended to drive it indoors with reckless abandon. (He was a bit of a rebel to start with.) He only says the word "NOOOOOOO!" when Frank comes after him with a pick ax, which is one word more than Rocky says. (Not counting their songs.) So, he theoretically could talk and knew crazy guy with ax=bad. Not bad for someone with half a brain.
 * Oh, because anyone with half a brain could tell that.

Live-Action TV

 * In a Just Say Julie sketch a Dumb Blonde supermodel is given a tricky question and her (tiny) brain explodes out of her head with the effort of thinking... leaving her seemingly none the worse for wear and not even bothering to cancel a date at end of the show to get medical attention.
 * A sketch on You Can't Do That on Television had a mother getting far too enthusiastic about cleaning out her child's ears, and cleaning out everything between them as well. It had no noticeable effect on the child (well, he wasn't *happy* about it but as his mother pointed out, even if she had cleaned out his brains he'd never used them anyway.)
 * Brain Guy from Mystery Science Theater 3000 is a variant on Type III: while his brain isn't in his physical head, he does always keep it nearby in a dish. If his body gets too far from his brain he degrades into a Type II. On top of all this, he and the rest of his species believe (in spite of all evidence) that their physical bodies don't actually exist.

Newspaper Comics

 * Over the Hedge occasionally has strips where Hammy the Squirrel's mind leaves his body and roams around independently. Since Hammy is a Cloudcuckoolander at best, this usually has little effect on him.

Video Games

 * In the Old World Blues DLC for Fallout: New Vegas, the player character has their brain removed (and their spine and their heart) and has it replaced with a bunch of machinery that basically connects their brain to their body wirelessly. When you find your brain towards the end of the DLC not only does it have its own personality, but you can opt to leave it out of your head for the rest of the game. With a couple of buffs even.

Western Animation
"Mr Burns: Oops. That stays in. (pops brain back into his ear)"
 * One Oh Yeah Cartoons short had a man literally sneeze his brain out. Aside from twitching every time the brain is poked, he acts perfectly fine.
 * In the Ren and Stimpy episode "Sven Hoek", both Stimpy and Sven can remove their tiny brains with no effect whatsoever.
 * An unusually violent (by the standards of the trope) Type III example in South Park: in 'Die Hippie, Die' Mayor McDaniels attempts suicide by shooting herself in the head. Just before she pulls the trigger the 'camera' pans to the side, we hear the gunshot and see blood and bits of brain matter hit the wall. Later in the episode she turns up alive and completely unfazed by blowing her brains out, with only a bandage wrapped around her head (with bloodstains on both sides of her head) indicating she'd shot herself.
 * In an even more violent (and extreme) example a different episode has Britney Spears survive a self inflicted shotgun blast to the head to that leaves her with nothing above her lower jaw. Since her 'speech' is now incomprhensible it's difficult to know which type she is but possibly a Type II (she seems too aware of the outside world to be a Type I.) This was apparently based on Mike the Headless Chicken.
 * In an episode of The Simpsons Mr Burns, having survived being buried under a landslide, is trying to get the dust and grit out of his ears by tilting his head and banging on the opposite ear. His walnut sized brain shoots out of his ear and lands on the floor.

"Homer: And stay out!"
 * In a more recent episode Selma insults Homer by saying he has a brain 'the size of superball'. Cue a cutaway to Homer's tiny brain bouncing around inside his head till it gets stuck in one of his ears, pops out his head and bounces away down the street. Homer is not only unaffected but actually seems pleased to see it go.


 * The Futurama episode "Roswell That Ends Well" has Bender's brain (a collection of computer chips) being mistaken for food and eaten. Bender isn't happy but he suffers no ill effects.
 * In the beginning of the episode "Dollar Day" of Fanboy and Chum Chum Fanboy's brain falls out when he trips, as a part of a Brick Joke. Later in the episode, when he and Chum Chum are trying to figure out how to get a dollar, he exclaims "We've got to THINK!", after which Chum Chum leaves the screen for a second to return with Fanboy's brain and places it back in his head. Throughout the episode, there's no difference in the brainless Fanboy's behaviour from his brain-equipped self (but he does make up a plan once he has his brain).
 * A variation on Type III is Billy in The Grim Adventures of Billy and Mandy. Billy is very much The Ditz at all times and it is revealed in Little Rock of Horror that he doesn't have a brain at all. That makes him a literal example of this trope: he never had a brain to begin with.
 * In another episode, Billy's dad accidentally eats his own tiny brain and is no less stupid than before.
 * In The Amazing World of Gumball, Gumball's brain gets out of his head after studying too hard. Gumball is unchanged, as he tries to train his brain so that it becomes smarter.
 * In an episode of The Fairly Odd Parents, Timmy drinks a smoothie too fast and says "Ugh... brainfreeze" which Cosmo replies to with "Brain? What is this "brain" you speak of?" and then proceeds to drink the whole smoothie in one slurp. "Nope.. nothing." Later, Cosmo and Wanda disguise as smoothies. Cosmo drinks himself in one slurp and still feels nothing.
 * Which is weird, because in another episode, Cosmo and Anti-Cosmo have a brain transplant.
 * Whenever a character on the show-even if they are not The Ditz-removes the top of their head, there will be nothing inside it.
 * In an episode of Spliced, Entree's brain catches on fire when he memorizes the entire dictionary. Aside from occasionally shouting random words, he suffers no ill effects. This also is apparently common enough for Peri to be able to tell.
 * In another episode, he is turned inside out, and is shown to have no brain.
 * In another, he is told that if he loses a game, he'll recieve 10, 000 volts of electricity to his cerebral cortex, and retorts that he doesn't have one of those.
 * In another, a mole-ster takes control of his brain and gets him to punch himself, so he pulls out the brain and pushes the mole-ster off.
 * In another, his brain, stomach and heart leave his body after getting sick of all the abuse they heap on him. He remains unchanged.

Real Life

 * Mike the Headless Chicken.
 * Though not all of the bird's brain was gone. Quoting wikipedia: "The axe missed the jugular vein, leaving one ear and most of the brain stem intact". Still, it is impressive.
 * Some animals.
 * Octopi are capable of thinking with their tentacles as well as their brain, so they can still move even with just a tentacle.
 * Frogs are still capable of various movements even without a head, though they do still experience some changes. However, a frog with its brain removed but its head still on, continues to act pretty much the same, and in fact has better reflexes than a frog with a brain.
 * Fruit flies can survive, fly, and even react to light sources without a head because insects have a ventral cord (which functions like a second brain) in their chest and light-sensitive cells in their kidneys.
 * A turtle's heart can keep beating unaffected even if removed from the body due to very strong cells that act as pacemakers.