This character is... barely a character. For a variety of reasons, he or she has gone past the Extreme Doormat and Stepford Smiler and become nothing. They aren't pushovers or empty of real personality, they are completely dead inside. They are this side of a Convenient Coma because there is still something there... they move, talk, eat, sleep, but they have no drive, ambition, or capacity for emotion. Basically, the body is an active biochemical machine, but the part that made him or her alive and human is gone.
In Real Life, the closest term for it is probably "catatonic". However, catatonia is as likely to result from the inability to initiate movement as it is from lack of consciousness; the individual could be anything from fully conscious to nearly comatose, and you could never tell.
How did this happen? Here's a few ways: regular old Crapsack Worldinduced trauma, psychological torture, Mind Control, Mind Rape, and high end uses of an Agony Beam. It can be done metaphysically by being drained of all their Liquid Assets or Life Energy, or having their Soul or part of their Soul Anatomy stolen. Then again, sufficiently radical body alterations can do this too, like being "upgraded" into a machine body or a less-than-successful attempt at resurrection.
Sometimes it's curable, others it's a permanent Fate Worse Than Death. Expect these characters to be the preferred People Puppets for Telepaths and demons for being not so much Weak Willed as No Willed. Contrast The Soulless, who are like Empty Shells filled with drive and ambition, and lacking all moral restraint. Compare to Soulless Shells, who died and were brought back without their souls.
Yuunote The real one, that is. opt to become in the 2012 anime of Black★Rock Shooter, due to the soul-crushing situation of her life.
In Darker Than Black "Dolls" are assumed to be this by nearly everyone (not only the Yakuza has no qualms over traffic in Dolls for Sexbot use, but efforts to save one were viewed as misaimed and pointless by those who knew what she is). Like with Contractors having no emotions, it was disproven, but they still are at worst comatose and at best submissive and so passive that people working with them all the time are surprised if they use their medium abilities without being told to, or show they care for someone. One was even successfully able to pretend that he was a corpse.
Suman Dark in D.Gray-Man becomes this after Allen manages to save him from being a Fallen One. And then Tyki Mikk explodes him.
In Flame of Recca, clone Aoi does this to the local healerYanagi by erasing her memories and pushing back her thoughts, removing her consciousness so that the satanic monster resulting from the fusion of two Complete Monsters, Tendo Jigoku, can absorb her soul without being rebelled by healing powers. It takes the timely arrival of her lover Recca to bring her back to her senses.
In the 2003 anime version, Tucker ends up creating one of these when he uses a Philosopher's Stone to recreate Nina's body. It's breathing and technically 'alive', but it has no mind and it has no soul.
There's also what happened to Ed's friend Rose Thomas as the show gradually slid away from the idealistic end of the Sliding Scale. She's left mute and pregnant after some soldiers who invaded her home town gang-raped her, ending up so empty that she was used first as a figurehead of a Religion of Evil, and then just as an unresisting body for the Big Bad to possess. She snapped out of it with Ed's help, and seems to have improved dramatically judging by her brief appearance in the epilogue.
Henrietta at the start of, and well into, Gunslinger Girl. Also after she gets reconditioned.
Rico: Welcome back, Henrietta!
Henrietta: Hello roommate, neighbour; I am home.
Happens to Agnieszka in Kurobara Alice. As the corollary to her Break the Cutie process, she stabs herself to death; a vampire named Maximilian, however, stabs her almost lifeless body with a magical blade, and renders her as this. The only way to "revive" her is to implant someone else's soul in her body; decades later, main character Asuza gives her soul in exchange for her boyfriend/student Kouya's life, and is transferred to Agnieszka's body... creating "Alice".
Metaophrically speaking, Kouya himself becomes this after Dimitri saves his life. When Alice (who once was Asuza) finds him again,. she sees that he's pretty much a pale shadow of the Ordinary Highschool Student he used to be.
Mazinger Z: The Iron Masks and Iron Cross are cyborg Big Bad Dr. Hell fabricated with corpses, mechanizing their brains (actually their helmets are a replacement for his skulls) and programming them to obey him loyally and without question. They have no name, no identity, no personality (and they barely have half face left under their helmets) and no family. They don't feel hesitate or fear and they don't fear death. And they don't mind.
Miharu, the main character of Nabari No Ou starts like this. He is indifferent to everyone and everything around him. The only thing he makes an effort at is being apathetic. He changes with time, though.
Neon Genesis Evangelion has Rei Ayanami, who starts out as one of many identical empty clone shells in the Reiquarium, with a new one taken out and uploaded with her personality as each successive one is killed. Of course, considering Rei's default personality, it is unclear whether there is a significant difference.
In Return To Labyrinth, Sarah qualifies. While not completely empty-shell, she has no real drive, desires, or ambition, and a large portion of her soul had been removed.
Happens in Rozen Maiden to dolls who lose their Rosa Mystica; they lose consciousness and become an ordinary doll (albeit with their eyes closed). It is implied though that their souls live on somewhere else, particularly in the manga.
Going by the once-Cutie Yukari Hirai early on in Shakugan no Shana, this happens to Torches as they gradually fade away from existence.
Texhnolyze: This is revealed to be the fate of all those living outside the underground city of Lux. Basically, the will to live has been drained out of them, leaving "ghosts" of their former selves. Lux was created to preserve what little will was left.
In the anime version of Sailor Moon, whenever someone has either their Pure Heart Crystal (S) or Dream Mirror (Super S) taken away, they almost automatically become this. They're seen in a lethargic state, with Mind-Control Eyes and almost unable to do/say anything. It's also stated that if they don't have them returned soon, they'll simply wither and die.
A similar effect happens when you get a shard of Nehelenia's broken Magic Mirror stuck in your eye in the first part of Stars. At first the victim will act normal if languid and obsessed with their mirrors (a girl screams and claims she's got almost no reason to live when Makoto knocks her handmirror off her hands), then they'll simply languish away until they die.
Death Note has this happen to Sayu Yagami, after she's rescued from a kidnapping by her father. It's implied that the sheer shock and fear that she went through while hostage caused her to fall into an unresponsive state, as she refuses to speak to her parents or move, to the point where her mother has to push her around in a wheelchair. Her last appearance in the manga (which wasn't included in the anime) is a brief cameo at a coming-of-age holiday ceremony in Japan. She's depicted as being able to stand again and smiling, though her eyes and overall expression still have an eerie vacancy.
The Emplate body is an example. Created to be a vessel for another character's personality, it becomes bestial and mindless when not 'occupied'.
One particularly nasty side story in Transmetropolitan involves Spider doing a story on child prostitutes in The City, who are disturbingly like this.
Man-Thing exists more or less in this state permanently, unable to hold onto any moments of temporary lucidity and motivated only by empathy.
ElfQuest devotes a plot point to an elf so tortured and mutilated by his captors that he has no arms, no legs, and no mind. He's got rockshaping powers, though, and can be prodded into using them in whatever direction they want him to, just to avoid worse pain.
Victims of the Anti-Life Equation in The DCU are turned into this. Forever and ever. And all it takes is to hear the Equation once. Fortunately, the Life Equation can counter it.
In her one-shot comic, Laura Kinney aka X-23 says that she was effectively this during the time she spent as a prostitute. Earlier, the Facility actively attempted to make her this, by depriving her of emotional connections and subjecting her to horrific physical and emotional abuse to strip her of her humanity, and her thoughts in her crossover with Daken reveal she had so little sense of self during her captivity that she truly didn't realize the things they did to her were even wrong. Her mother even believed they succeeded until Laura revealed Rice sent her to kill Martin Sutter and his family, and that she chose to spare her son, proving that however severe the damage she still held on to part of her humanity.
"And even though he was the only one who walked out of that town alive, inside he still felt like he died that day. There was nothing inside of him anymore; happiness, sadness, anger…he felt none of those emotions. Instead, only his corpse dragged him on."
Immediately after Twilight first casts Starswirl’s incomplete spell in Divided Rainbow, all her Element Bearer friends temporarily enter a vacuous sleepwalker-like state, as they're compelled to physically switch places with each other geographically. Rarity has to endure this the longest because at the moment the swap took place, Rainbow was in the middle of a dangerous forest, many miles away, trying to save Lero’s life. This state wears off over time, and by the time she actually reaches Lero, she's mostly back to normal.
In Duel Nature, Luna's Badass Boast mentions having torn the souls from her enemies, leaving them as lifeless shells.
In Fate Megami Atelier, Hikawa tries to restore harmony and peace to torn dimensions... by removing everyone's emotions.
For a couple of days after a traumatic challenge accident in The Legend of Total Drama Island, Lindsay is only dimly aware of her surroundings. She doesn’t even have enough self-awareness to eat or use the toilet without assistance.
In The Lion King Adventures, Shauri's victims in Return to Camp Kazi become literally this, and in Series 5, Simba would become this metaphorically.
Richardson threatens to do this to David in The Adjustment Bureau, obliterating his mind so completely that there would in essence be nothing left of him.
Podling who have their essence drained in The Dark Crystal become this, turning gray and empty eyed, shuffling from place to place. Happily, it was cured when the Dark Crystal was healed.
In the horror film Pulse, ghosts drain the "will to live" from people, turning them into Empty Shells that just want to die.
The chemical Pax caused most of the population of Miranda to sit or lie down wherever they were and do nothing until they died, in Serenity. The remainder had the exact opposite reaction, becoming the psychotically violent once-human monsters known as the Reavers.
In Mad Max 2, Max is described as a "burned out shell" by the narrator.
In later books, we also see that Neville's parents became empty shells after prolonged torture—they lost most of their brain functioning and barely seem to recognize their son.
In Mostly Harmless, Arthur Dent spends some time on a planet which seems a lot like Earth but where no one has any motivation or hopes at all, and apparently don't even care enough to avoid dying of thirst when their plumbing breaks.
In the Discworld novel The Light Fantastic, Trymon becomes one after his mind becomes a door into the "Dungeon Dimensions", whence strange, horrible creatures try to escape into reality.
In His Dark Materials, there are creatures known as Spectres that feed off of adults, turning them into Empty Shells.
This is also usually the fate of those who have their daemons severed.
The ultimate fate of the protagonists in 1984. The Ministry of Love mass-manufactures such people.
People caught by the Black Wind in The Wheel of Time series become this, if they survive. Likewise being "kissed" by a Draghkar, or otherwise losing your soul. There are also the Grey Men, sometimes known in-universe as The Soulless, who have surrendered their souls to the Shadow and are little more than automatons. Finally, Mesaana becomes this in book 13 after she wasdefeated by Egwene in Tel'aran'rhiod.
Perhaps the nastiest version — the Borg are this, according to Star Trek: Destiny. The guiding intelligence of the Borg was once an alien cybernetic organism called a Caeliar — a bit paranoid and xenophobic, but basically okay. But after being stranded in the past with nothing to sustain her, Sedin degraded into a mindless hunger.
Scott Tyler in The Power of Five is one of these at the end of Nightrise. Probably understandable, considering he spent most of the book being tortured, both physically and mentally.
Some of Isaac Asimov's robots became like this if they got stuck in the robot equivalent of a really bad infinite loop (eg, by running into a Three Laws conflict that couldn't be resolved without hurting at least one human. The smarter ones found a solution that minimized human injury; simpler models just went insane.)
Within the Gentleman Bastard series, this is the result of inhaling the smoke of wraithstone. It's commonly used on animals to "gentle" them, effectively removing all desire other than a mild desire to eat, sleep, and follow commands. It works on humans too...
Battle Royale demonstrates why this can also be a bad thing for those around the Empty Shell. Kazuo Kiriyama was brain-damaged at birth, and his emotional responses are extremely limited. With no feeling of reward for accomplishment, he's been drifting through life, and with no sense of guilt, he has difficulty resolving moral dilemmas. When forced to kill his classmates to survive, he can't tell whether it would be better to fight it and potentially get himself killed too, or go along and ensure his own survival if nothing else. A coin flip resolves things in favor of going along, so he calmly, emotionlessly kills as many students as he can as fast as he can. In the manga, there's even a chapter that calls him a Devil of Nothingness.
At one point, there's a flashback to when a group of kids became Kazuo's friends; he flipped a coin and decided to go with them. In the modern day, they're present when he flips another coin, and once it lands, he starts killing them. One of them realizes, as he's dying, that the only reason he didn't kill them when they met was because the coin landed in their favor.
In Robert Silverberg's novel Recalled to Life, a process is invented that can restore recently dead (i.e. within a day or so) people to life. (It doesn't actually heal whatever killed them, so it's mostly useful for drownings and the like.) One catch: there's about a one-in-six chance of restoring a mindless shell.
Colonel Armitage in Neuromancer. The mercenaries he's hired suspect that he does nothing but sit and stare at the wall when he's not on the job.
Debatable, but... Bella from Twilight becomes this during New Moon while Edward is gone.
In Harmony by Project Itoh, Harmony is supposed to be a program which controls human will via Nanomachines to make human decisions perfectly logical and beneficial for society, but in the process it turns people into this (since the main conceit of the book is that consciousness is formed from the brain weighing up the benefits of various actions, and since Harmony does this task for people, humans stop being conscious). Somewhat averted, though, because Empty Shells under the influence of Harmony are perfectly functional human beings and experience pure, total bliss, compared to Heaven on Earth - they just have no inner voice.
In Animorphs,the Ellimist's back story involves him being captured by Father, a huge sea creature that absorbs/enslaves the minds of others. Eventually the Ellimist learns to absorb those dead minds from Father into himself. At the end it seems that Father had no real mind of his own, just a Hive Mind from everyone he had absorbed.
Possibly the Isk, created by the Yoorts and together making up the Iskoort species.
At the end of The Moon Is a Harsh Mistress, this seemingly happens to the self-aware supercomputer Mike. For reasons unknown, after the final battle he loses his personality (or becomes catatonic) and reverts back to being "just" a computer. He's not physically damaged, and he continues to function perfectly as a machine... but he is no longer anything but a machine.
In Anne McCaffrey's Dragon Riders Of Pern series, this can happen to those whose dragons die. Some snap out of it, others never do.
In The Hunger Games, this happens to Katniss's mother after Mr. Everdeen dies in the mines. Then Katniss goes through it twice: first after Peeta is captured by the Capitol at the end of Catching Fire, then after Prim is killed in Mockingjay.
The Fablehaven books have revenant victims and people who looked into the Oculus unprepared, all of whom lost most of their brain functioning.
Null Achtzehn ("Zero Eighteen") from Primo Levi's Holocaust memoir If This Is a Man.
In M.C.A. Hogarth'sTales Of The Jokka stories, this is the inevitable fate of females. All Jokka risk "Mind Death" if they become overheated or stressed, losing all ability to reason. Males and neuters can avoid this by taking care to avoid pushing themselves, females can't avoid the stress of childbirth however. Every birth runs increasing risk of inducing further senility for the mother, until their mind is completely gone.
In Dollhouse, the Actives are supposedly like this between missions, although evidence suggests that this may not be as complete as the characters believe.
The characters know it, too. To wit: Topher's aversion to the Actives "grouping", or making basic friendships that endure through wipes. The same processes that creates the "grouping" effect can cause the chance of a "composite event", or the Active gaining access to all their previous personas at once, because it penetrates through the wipe.
In Season 6 of Buffy the Vampire Slayer, Buffy sees herself as being this trope, stating multiple times that she can't feel anything since she was traumatized by being brought back from the dead. This also constitutes the theme of most of her songs in the musical episode. She isn't really an empty shell though, and gets better by the end of the season.
Played with on Angel, in "Soul Purpose". Angel is coma-dreaming about Fred doing surgery on him and she tells him "There's nothing left, just a shell", an allusion to what Wolfram and Hart is doing to him. It's also irony since she became a literal shell for Illyria.
The Star Trek: Deep Space Nine episode "Life Support." Vedek Bareil dies and is then resurrected, but for him to survive, part of his brain had to be replaced with positronic implants (the same stuff Data's brain is made of). He is able to function but he is very different, almost emotionless, and describes his sensations as vague shadows of what he remembers. Eventually, when the rest of his brain starts to fail, Doctor Bashir allows him to die rather than replacing his entire brain with artificial implants. Also an example of Cybernetics Eat Your Soul.
In Supernatural, acting as an archangel's vessel leaves you like this when said archangel leaves.
In Warehouse 13, this is the eventual effect of Evelyn Waugh's Typewriter, which is kept in the Dark Vault.
This is one of the ways to describe what happens when you lose all of your charisma (by being poisoned or subject to magical draining attacks, for example) in Dungeons & Dragons. Losing all Wisdom — a measure of a character's mental balance, the base stat for Willpower — causes you to "fall into a nightmare-filled sleep." Losing all your points in any vital stat generally means you can't act at all and automatically fail checks based on that stat until you recover at least one point in it - the exception is Constitution, which measures your health, and if that falls to 0, you simply die.
This is what happens to people who stay too long in Hades, the lowest plane of the lower planes in the default cosmology. The idea presented is that pure evil is not torture or manipulation; it's the complete loss of hope.
The upper plane of Elysium has an "entrapping" trait almost identical to Hades, except it operates through contentment rather than despair.
In the Ravenloft Campaign Setting, people who see horrible things have a chance of becoming "Lost Ones," who are essentially catatonics who cannot take care of themselves.
Waisen from 7th Sea's Eisen are like that. Thirty years of war can do this to helpless civilians.
In In Nomine, this is what happens to angels and demons who lose all of their Celestial Forces; They become Remnants, wandering the Earth in whatever body they last used before they were killed, without the perception to remember what they were or the will to do much of anything. Angels and demons alike tend to consider them both sad and creepy.
She Who Lives In Her Name's Charms can do this too. Oddly enough, she also has one which can refill the dream-eaten left behind by the raksha, although they'll never be who they used to be.
This is the theme of The Ebon Dragon (other than being a cosmic dick). He is so empty inside that he doesn't have a Motivation, a state that is normally impossible for something that exists. His Charm that enables this abnormality? Ego Shell Ascendancy. And that's not even the worst of him: it's implied that back then he wasn't merely empty, he used to be not existing and was only able to affect the world by being an empty mockery of someone else.
In the third party D&D 3.x setting Diomin, Hollow Ones are not alive, not dead, and not undead. They are removed from "the web of life" and concerned only with eating and stealing, and they go berserk when "bloodied".
This is what happens to Kairi in Kingdom Hearts when her Heart leaves her body and enters Sora.
Also of note are the Nobodies in the second game; the body of someone who has had their heart stolen by the Heartless. In most cases, the shell is transformed into a shapeless monster. They have no emotions of any kind, as they have no 'heart', but the Nobodies of people with particularly strong hearts retain their memories and human appearance. They know what it means to feel, but will never do so again, (sometimes) through no fault of their own. They want Sora to kill as many Heartless as possible so that they can build a Kingdom Hearts that can restore their lost hearts. We later find out in Dream Drop Distance that they aren't actually quite as empty as they were told, and were only told that they were so that the tiny bit they had inside wouldn't develop enough to protect them from being possessed by the Big Bad.
Similar to the Kairi example above, this happens to Ventus when his heart leaves his body and enters Sora.
This also happens very tragically to Sora himself when Master Xehanort's younger self shatters his heart, though this is different than the other two examples, in that the shards remain in his shell. This does not last long, thanks to Riku.
Shedinja from Pokémon Ruby and Sapphire onwards. It's literally an empty shell with nothing inside, the discarded remains of an evolved Nincada's exoskeleton.
Shedinja's hard body doesn't move — not even a twitch. In fact, its body appears to be merely a hollow shell.
There have been, in fact, cards for Shedinja in the Pokémon Trading Card Game who have the special ability "Empty Shell."
According to legend, Azelf can cause humans to lose all will inside of them, making them completely immobile. Uxie can wipe your memories as a human, and Mesprit can strip your emotions clean. All three of these are likely to do this if you really piss them off. They are, at least, respectable in that they don't use these powers when trainers play with them in Pokémon battles.
Shadow Pokémon, which themselves have their emotions wiped clean in some of the worst implied (human-inflicted) Mind Rape the series will ever know. All of this because those in charge of Cipher want military power for their campaign of global conquest.
Ghost Trick: After he's struck by the meteorite fragment, Yomiel's body becomes trapped in stasis at the moment right before his death. Wounds heal instantly, hair doesn't grow, and he's neither truly alive or truly dead. Even after he's reunited with his body he feels a crushing sense of isolation from the rest of humanity that eventually drives him to seek mindless revenge on everyone involved with his death.
The epic spell Entropic Husk from the first Neverwinter Nights 2 expansion annihilates the target's soul, leaving nothing but a body that randomly attacks whatever comes near it.
Akachi from the same game is nothing but an empty shell of hunger. Myrkul, his former god, had his soul destroyed to the point where there was nothing left of him but a sense of emptiness.
Furthermore, the Big Bad's plan to end discrimination involves killing half of the world's population and turning the other have into "Lifeless Beings" (AKA: This).
This happens fairly rapidly to Kohak Hearts in Tales of Hearts. The first half of the game is getting her emotions back. After that... other things happen. She doesn't even fight in battle until you get back her courage.
Canas: ...Unfortunately, the darkness took my brothers... They live...and breathe... their eyes open and close... But...they do not move. And they do not speak.
And in the same game, Bramimond takes this just about as far, but no in the same way. He basically gave up his soul for the power to fight dragons and now he simply reflects the soul of whoever is in front of him. While dark may not be evil it most certainly is not a toy
Fire Emblem: The Sacred Stones has two tragic instances of this. Emperor Vigarde of Grado died and was revived via dark magic, as was the wife of the traitor to the good guys, Orson, who defected after it was promised his dear Monica would be revived. Sadly, Emperor Vigarde is a husk that barely resembles the persona of the man he once was, and Orson basically gets a zombie version of Monica who can only say the word "Darling...", and she apparently has started to decay so much by the time you slay said traitor that the good guys give her a Mercy Kill. As a further tragic note, even after "getting Monica back", Orson realized on some level his wife was actually still dead, and trying to maintain the illusion her zombified shell was the original drove him completely insane.
The Horned Girl from Baroque is an Empty Shell, who, lacking any thoughts of her own, instead repeats aloud the thoughts of those that try to speak to her.
In Persona 4, Mitsuo Kubo'sInner Shadow is a Nietzsche Wannabe Empty Shell. Since his Shadow is as much a "true self" as the shadows of your other party members were their own "true selves", it implies that Mitsuo is driven by the subconscious fear that he is insignificant and will never amount to anything. As a first for the game, Mitsuo is unable to see through his own delusions of grandeur and own up to his own insecurities, unlike your party members, and his Shadow simply dies as a result.
Maria from Gears of War 2 is like this when you "rescue" her after she's been tortured, starved, and mutilated by the Locust. Dom euthanizes her.
Noel Vermilion, AKA Mu-12, was created as an Empty Shell. Her Murakumo unit "tempering" was interrupted, allowing her to develop a personality, albeit a very weak and passive one.
An odd case is Lambda-11, an uncompleted Murakumo that was fixed up by Kokonoe (though kinda downgraded) and mind wiped so she could be powered by the soul of Nu. There's a breif flashback before the mindwipe that shows her having some awareness and personality, and even after it she still develops a very small amount of a personality in the story, espicially in her gag reel. And despite not being a true Murakumo unit, Nu's personailty and memory flashes through sometimes, most notably when Lambda takes an attack meant for Ragna in the true ending.
Mass Effect: The Reapers control their victims through a process called indoctrination. Prolonged exposure to Reapers or certain Reaper artifacts Mind Rapes you, eroding your brain until you are a perfect servant of the Reapers, incapable of doing anything the Reapers haven't told you to do. Victims are used as sleeper agents or turned into Husks. Ultimately, they are abandoned to starve when the Reapers return to dark space or repurposed as a slave race. The Collectors are Protheans turned into a slave race.
In Mass Effect 3: Leviathan, the eponymous species has a similar technique known as "enthrallment" which was the basis for indoctrination, as the first Reaper was created from the essence of the Leviathan. Active long-term thralls have a tendency to move mechanically and speak awkwardly if at all. However, thralls can act more naturally to facilitate infiltration operations. Fortunately, unlike indoctrination, enthrallment is not permanent, and operates only while the Leviathan or one of its artifacts is in proximity of the victim.
The Tranquil from Dragon Age: Origins. If mage apprentices are too afraid to go through the Harrowing, the final test to see if they are worthy of becoming full-fledged Circle mages, they can instead choose to have their connection to the Fade severed. This removes their ability to perform magic and along with it any threat they might pose due to uncontrolled magic. Since the Fade is the realm of dreams and spirit the process also robs the Tranquil of their ability to feel. They can't even feel fear when the Circle is overrun by Abominations; though one does mention that he would prefer not to die. That's the closest thing to an emotion that any Tranquil expresses in the game.
If you speak with Owain during the mage origin, however, he argues (well, states) that Tranquil are closer really to The Spock. In his own words, he does not currently believe that being incapable of emotion lessens his worth as a human being, and even though he has no drives or ambition any more he isn't incapable of acting on his own.
On the other hand, Dragon Age II shows what happens when a Tranquil mage briefly regains emotion - he begs you to Mercy Kill him before it wears off. The qunari have a substance called "qamek" that produces similar results. If a prisoner refuses to convert to the Qun no matter what, it converts them into a mindless laborer.
In Shin Megami Tensei: Strange Journey, this is what happens to humans who fall victim to Zelenin's song, becoming unable to do anything but praise God mindlessly. In the Lawful route, this is the fate of all of mankind (or, at least, those who aren't destroyed by the Schwarzwelt wave for not being "worthy" enough): singing God's praises for all eternity, in perfect and absolute harmony, with no emotion, no conflict, no creativity, and no life.
The end result of being a Zuul captive in Sword of the Stars. The Zuul systematically Mind Rape their victims with their Psychic Powers, ripping their knowledge, memories, thoughts, and eventually their very identities from the victims' minds and leaving them catatonic husks. Even partial exposure is often enough to cause either this trope or simply turning into a gibbering wreck with all of their memories and knowledge jumbled up and full of holes.
In the bad ending of Shadow Hearts Covenant, Yuri ends up like this as a result of the Mistletoe curse finally devouring his soul and his memories. He is taken under Roger's care after that.
Starcraft: The victims of the Terran Dominion's neural resocialization, a brainwashing process to create new soldiers, would be considered this, or at the least Extreme Doormats. According to the wiki, the minds of a resocialized person are described by telepaths as being "fuzzy" and lacking the depth of personality found in ordinary humans, possess little to no initiative, and will shift loyalties if their commander does so as well.
Knights of the Old Republic II: The entire crew of Darth Nihilus' flagship, The Ravager are like this from having their life energy, willpower and sense of self drained by Nihilus' presence. They are incapable of individual thought, speech or anything outside of their task on board the ship, which they perform like lifeless mechanical drones. On board the ship, your character encounters Colonel Tobin, the Smug Snake who shot down your freighter earlier in the game, this time as an eerie, zombie-like◊ man at the edge of his sanity, just from being on Nihilus' ship for a few days.
Oichi in the third game of the Sengoku Basara series verges between this and Extreme Doormat. Her mind appears to be mostly gone as she speaks entirely in Ironic Nursery Tunes and Word Salad which makes her sound like she's asleep, she has no opinions or drives any more apart from what she picks up from others, and she seems mostly unaware of her surroundings. If it hadn't been for the demonic hands dragging her body along like a puppet, she probably wouldn't even be mobile.
In Baten Kaitos Origins, talking to NPCs in Tarazed reveals that the trauma of losing your wings can lead to this.
Maiev in World of Warcraft claims to have become this after the death of Illidan because, as Illidan put it, the huntress is nothing without the hunt.
In Dark Souls Undead that have lost all their humanity turn into mindless hollows, which usually come in two flavors; Ax-Crazy or huddled in a corner crying. This is also the fate of Gwyn, the Lord of Sunlight after a thousand years of burning alive in the Kiln.
In Fallout 3, some of the Point Lookout tribals became like this after their lobotomies.
Even worse, Fallout: New Vegas: Old World Blues has the appropriately-named Lobotomites, who have had their entire brains replaced with Tesla coils, retaining only the ability to perform simple tasks. The player is given a similar treatment, but retains a link with his/her disembodied brain.
In Heaven's Feel, he's even more broken After receiving Archer's arm, he can use it to greatly enhance his power, but each time he does so, his body is warped into a physical embodiment of his Reality Marble...turning his body into steel, and erasing his mind. If he does this too much, he is reduced to a mindless automaton, his body pierced from the inside by all an infinite number of swords that creak and moan with every step, and the only thing left of his personality is the single-minded desire to save the woman he loves. he does so, and he simply...stops.
Kotomine is a similar example, lacking the ability to feel any positive emotion save pleasure in the suffering of others. He tried to fill his life with good acts to counter his abberant nature, but has ultimately concluded the only thing he truly desires is to unleash Angra Maniyu so he can learn why he was born such a broken being.
In Tsukihime, Akiha ends up like this in her Normal Ending.
This is what happens to Beatrice as a result of the end of Ep4 in Umineko no Naku Koro ni. It isn't until the beginning of Ep5 that we actually see the effects, though. Basically, she is incapable of doing anything by herself and sits there with a lifeless expression on her face for a good chunk of the game. Massive Ship Teasing with Battler ensued.
Webcomics / Web Original
In Dan and Mab's Furry Adventures , if a fae actually biologically has a child with any non-fae, the result is an empty husk that dies on their 21st birthday. This is because there can only be a certain number of fae at any one time, and to make a new fae an old one must decide to die.
At some points, Nessiah has been like this in Dept Heaven Apocrypha. It's not the straightest example, as the state was intentionally induced through a heavy cocktail of sedatives; the idea being that his massive mental trauma can only be repaired by slowly nursing him back to sanity as the drugs wear off.
In El Goonish Shive, possession by a body snatcher aberration seems to result in the original person becoming this.
The Nostalgia Critic's Heroic BSODs are frequently going into this territory more and more as time goes on. He always manages to crawl his way out of it so he can continue life, but the implications are nasty considering how Hot-Blooded he usually is.
Horuss Zahhak of Homestuck believed he was this until he listened to the Void inside of him. Then he pretty much went batshit insane.
Oni Lee, a teleporter capable of temporary Self-Duplication, also suffers from this, apparently as a result of overusing his power. He's described as "a robot waiting for orders." A robot, to be clear, that can turn himself into a teleporting repeat suicide-bomber.
Zombunny of an early 1990s TV show Dr. Zitbag's Transylvania Pet Shop is a zombified rabbit who never seems to move. None the less, this has never stopped Dr. Zitbag from using Zombunny to mind the pet shop, baby sit, or perform other tasks he's clearly incapable of performing. The running gag is that Zombunny always manages to succeed through the power of doing nothing.
The alternate universe of the Justice Lords in Justice League has Well-Intentioned Extremist Superman using his heat vision to perform crude lobotomies on Batman's most dangerous criminals and, now barely above mindless zombies, placed in Arkham Asylums. It's truly disconcerting when the group meet the lobotomized Joker in an abnormally calm and docile state but heartbreaking when the Flash happens to encounter the lobotomized version of Poison Ivy, who now has no signs of her former ambitions and no longer cares what happens to the world and its plants. Even though they were villains, the ruthless lengths the alternate Superman was willing to go through to maintain order places him squarely in Moral Event Horizon territory (if he hadn't already crossed it in his first appearance already).
This was what apparently happened to Gorilla Grodd in his first appearance after Flash "crossed a few wires" in his mind control helmet and tricked him into using it. This fried his brain and turns him into a brain dead vegetable. But Grodd not only recovered from this, but no longer needed the helmet to control minds.
Dr. Destiny also ended up like this after overdosing on sleeping medicine and overexposure to the dream machine. In his last appearance in the show, he is lying in Blackgate's hospital, comatose with his eyes open and humming "Frere Jaques".
"Phineas and Ferb Get Busted" has this happen to the boys themselves. Don't worry, they snap out of it.
In Drawn Together, Spanky Ham justifies his and his housemates' killing of the staff of Entertainment Weekly by stating that working in cubicles has made them already "dead inside".
Dr. Viktor's body was said to be this in the Ben 10: Ultimate Alien episode "Viktor: The Spoils", prior to it's possession by the consciousness of King Xarion.
With Depression it can feel like this. Note if you do feel like this please seek help.
Curiously averted in the concept of a philosophical zombie, a creature in a thought experiment that has no soul/mind/internal experience but acts exactly as if it does, eg. exactly like a person. See also: Zombies: The Movie.
Some portrayals show modern office settings as this, essentially people becoming cogs in the machine and slowly losing emotion in their lives. Whether or not this is accurate is up to the individual.
Prisoners can become like this after long periods of solitary confinement.
There are two types of Wild Children or feral kids: those who have lived isolated from human contact brought up by animals and those who live in complete isolation due to Abusive Parents. This becomes a major Tearjerker because unlike the former, who at least have the care and attention of animals to keep them company, the latter are completely and totally isolated from any form of contact whatsoever, causing them to become severely developmentally disabled and withdraw into themselves. A particularly bad case was Dani, a young girl who was locked in her room and deprived of human interaction for the first 7 years of her life, wallowing in her own feces and with only cockroaches for company. When finally rescued by child services, she had a perpetual Thousand-Yard Stare, did not react to heat or cold or even pain, didn't respond to hugs or affection, and couldn't even use her hands. (Although she is improving from her care.)