"Better safe than sorry, Better safe than sorry, Better safe than sorry, I can't believe he bit me!! Better safe than sorry! I, I opened the door before and I got bit for my trouble. No. Won't fool me twice. Better safe than sorry! Better safe than sorry!"
Domina No Do has Ayako, where after having a yandere moment, travels with the Domina's Family grandmother, sending a note to Takeshi for him to wait for her. The phrase "wait for me" goes on for several pages, growing increasingly erratic with each new line.
Tsukihime: This chair. This chair. This chair. This chair. This chair. This chair.
Sailor Moon: ''I won't forgive you. I won't forgive you. I won't forgive you. I WON'T FORGIVE YOU!!" from the first episode of the 5th season.
In the last season, when Galaxia reveals that she's killed Tuxedo Mask, Sailor Moon is briefly reduced to only being able to say "Mamo-chan...is dead..." over and over.
A much more prevalent one throughout the second half of season 4 is "Yume yume itagau koto dakare; yume miro kodomo no yume no yume", translated in the subtitles as "Dream dream don't doubt it; a dream of dreams that children dream".
"LET'S GET MARRIEDMARRIEDMARRIEDMARRIEDMARRIEDMARRIEDMARRIED...''" (Although, to be fair, they don't have mental breakdowns, they're both just consistently crazy.)
Bokurano: "There's no way Dad could've died, there's no way Dad could've died, there's no way Dad could've died..." Said by Kodaka after he accidentally crushes his father while piloting a Humongous Mecha.
Joshua from Chrono Crusade launches into a chant of "Sis. Sis. Sis. Sis. Sis." on at least one occasion.
One episode of Witch Hunter Robin features an obsessive-compulsive witch who, when confronted by the main characters, starts repeating, in an increasingly panicked voice: "You soiled... you soiled... you soiled... you soiled... you soiled... you soiled..."
Made hilarious in the outtakes: "I mustn't run away, I m-ok, I got that, good, ok. Now, if I were to run away-let's analyze that-, where the fuck would I go?!"
Then there's Asuka's "I don't wanna die! I don't wanna die! I don't wanna die!". It becomes even creepier when her mother's "You are not alone. You are not alone. You are not alone" gets piled over it. Unlike Shinji's example above, Asuka's mantra does work. For about 15 minutes.
It becomes even creepier still when you realize that interspersed with her mother's "You are not alone." is the shrill voice of the half of her mother that went crazy and hung herself shrieking "Please die with me!"
Asuka also muttered "I'll kill you... I'll kill you... I'll kill you... I'll kill you..." when she made her unpowered, impaled and gutted EVA move via sheer force of will. For about 40 seconds.
What about Shinji's "I can't take it anymore... I can't take it anymore... I can't take it anymore..." from EoE? That one really counts as a Madness Mantra since he's losing his grip on reality at that moment.
When Johan begins to explain his intentions to Nina The end...the end...the end...the end...the end...the end...the end...the end...the end.
This little snippet from Episode 29: Dr. Gillen is interviewing the murderer Peter Jurgens. He shows Peter a picture of Johan and Peter says that he does not know him, and then he asks him for a pen. He takes the pen and begins shading around the face of the man in the picture. He tells Dr. Gillen that on the second day of the murder, he had gone to the park; he was telling himself that he wanted to stop, and then he saw the man surrounded by children there. Peter then repeats the words "You should come too" (or "Come with us" in the English dubbed) over and over again while some ominous little tune plays and the camera does a close up on his expressionless face. He then takes the pen and plunges it into his right ear. Blood squirts out and he falls over dead.
The Big O: "There is but one truth. If you avert your eyes from it, you will always remain nothing more then a puppet."
In Eureka Seven, after Charles Beams dies, Ray spends most of an episode humming an eerie tune. Made even more creepy by the fact that the audience barely sees her, just hears the humming over scenery shots of the rooms she's trashed.
After a pressure cooker of stress detonates in his head, Renton has a menacing freakout in the midst of a firefight with human-piloted enemy mecha. Suddenly, he's butchering them all to pieces in a swearing fit of "DAMMIT," punctuated by horrendous amounts of gore as he enters a berserk rage and starts killing them all like a rabid beast. Nirvash spawns red, glowing eyes as Renton mangles them all, finally leading up to a when he sees an evil shadow with his own face, laughing maniacally. Renton peels open the last mecha left intact, screams wildly, then stamps Nirvash's boot down on the exposed cockpit with the pilot still inside, squashing him like a bug. Unfortunately, what was left of him- namely, tons of blood and the severed arm of a married man- hitched a ride on the sole of the boot- which Renton saw crystal clear. Immediately followed by total Heroic BSOD, My God, What Have I Done?, and vomiting. Made even worse that the only discretion shot was for the puke, NOT the bowel-loosening gore.
Berserk has Theresia's "Just take me back to my room."
Hell Sing has Seras going berserk after Zorin Blitz kills Pip and refers to him as an insect and screaming "Unforgivable...Unforgivable...Unforgivable...Unforgivable!" or "You'll pay...You'll fucking pay. You'll fucking pay. You'll fucking pay!" Also, after she drinks from Pip and becomes a powerful vampire she says "Let's slaughter Pip...Slaughter...Slaughter!"
SHUFFLE!. Kaede in episode 19 repeating at Asa (japanese sub) "Go back. Please go back...Please go back...Please...go back...Go back...Go back...GO BACK! GO BACK! GO BACK!" or (english dub) "Get out. Get out of this house. Get out of this house. Get out... Get out.... Get out. Get out! OUT! GET OUT OF MY HOUSE! GO AWAY!"
From Casshern Sins, the hoards of robots that believe devouring Casshern will grant them eternal life are always shouting the same thing.
KILL CASSHERN! DEVOUR CASSHERN!
Jeremy a little bit in A Cruel God Reigns. He repeatedly says "Hallelujah" at one point while being beaten by Greg.
After the Chameleon snapped in one issue of Spider-Man, all he was capable of saying was "Nothing nothing nothing nothing..."
In Grant Morrison's run on Animal Man, the Arkham inmate Psycho Pirate chants phrases such as, "Worldswillliveworldswilldie," and "One and two and ess and ex and three and four and prime." These turn out to be Arc Words, referring to the parallel Earths variously merged or destroyed in Crisis on Infinite Earths some years earlier. The Psycho Pirate is the only one in the DCU who remembers these lost worlds, and so these Madness Mantras allude to, respectively, DC's promotional tagline for the Crisis crossover and the names of various parallel Earths (Earth Two, Earth S, Earth X, etc.). His ravings are a premonition of the temporary reemergence of superheroes and supervillains from the lost Earths.
In an issue of The Flash, Wally's ex-girlfriend Tina McGee calls him for help because she believes there is something wrong with everybody around her. When Flash gets there he finds that she is at her keyboard, repeatedly typing "I'magoodgirlI'magoodgirl". Everyone thinks she is having a nervous breakdown, but actually her colleagues have been taken over by the Kilg%re, and she's perfectly alright.
"He won't have a gun, Trust me Ashley. He won't have a gun, Trust me Ashley...
In an issue of Justice League, the Atom has the song Stardust stuck in his head throughout the issue, but can't remember all the lyrics. He and the other leaguers soon encounter an alien probe named Mnemon, who steals memories. After temporarily stealing the memories of the league, it is defeated and ends up drifting through space with just one memory that it repeats endlessly: the song Stardust. And it still doesn't know the words. A nice combination of this trope and Earworm.
In V for Vendetta," after V destroys Lewis Prothero's priceless doll collection in front of him, he goes insane, and can only say "mama, mama."
Interestingly, the speech bubble cuts him off before with "ANIMALAN—", or, as it could be read "an' I'mAlan."
Kurt Gerhardt, the third Foolkiller, used "Bingo Bango Bongo".
You know things are bad when Superman starts using one of these: during Grant Morrison's (Is there a pattern here?) run on JLA, in fact near the end, in "World War Three", Supes has his hope and will broken by the Old Gods' death machine from the edge of space, Mageddon. While under the influence of the doomsday device, he compulsively utters... "We can't win over this... the end of it all... oblivion... MAH-GED-DUN.."
In The Precious Book, Harry set great store by a copy of Alice in Wonderland given to him by a kindly bookshop owner, regarding the characters as his friends. When Quirrel used a mind control curse on Ron Weasley to make him destroy it, Harry spent several heartbroken weeks doing little but sob "Murderer" over and over again.
Queen Of All Oni has Jade's thought processes degenerate into this when Lung tortures her trapped astral form.
"Gotta get away, gotta get away, gotta get away, gotta get away, gotta get away, getaway, getaway, getawaygetaway..."
In chapter 13 of Passageways a time-travelling Harry attacked Abraxas Malfoy and several other Death Eaters after they showed up to terrorize Diagon Alley. When Malfoy saw the lordship ring of a formerly-extinct family on Harry's hand, he lapsed into shock and kept repeating "It can't be..."
The Magdalene Sisters: Crispina, a handicapped girl of the Magdalene Asylum, was routinely sexually abused by the Padre, as revenge another girl contaminated his robe frock with itching powder, which inevitably Crispina contacted with. As the Padre runs off into the woods disrobbing, while giving a sermon, Crispina, snaps and chants out "You're not a man of god, you're not a man of God, you're not a man of God......" many times with increasing fevor expressing her humiliation and frustrations, of physical and mental abuse in the convent. The audience, either claims this mantra was over done, And or, NOT ADEQUATE enough to compensate for the abuses she has suffered especially in light of her mental challenges.
This is hinted at in the ads for Dont Say A Word, by the young woman in the asylum repeatedly muttering "I'll never tell!" in singsong. Her actual madness is a matter of conjecture, but the phrase proves important to the plot.
In the novel, the disorganized schizophrenic Sammie (replacing Hannibal's former cell-neighbor, Multiple Miggs) has a very distinctive mantra that apparently started some time after he put his mother's severed head on the Church collection plate:
I WAN TO GO TO JESA, I WAN TO GO WIV CRIEZ, I CAN GO WIV JESA, EF I AC REEL NIIIZE!
Hans Beckert's whistling of "In the Hall of the Mountain King" in M probably counts.
In the aftermath of Batman Forever, Edward Nygma, a.k.a. the Riddler, is reduced to repeating "Too many questions...too many questions..." after his brain is overloaded by the malfunctioning Box. This was once a rant by Nygma, spawned by his boss and idol Bruce Wayne rejecting his project by saying that it raised "too many questions."
Split Second had "Big guns. We need big FUCKING guns!" as a character's Madness Mantra after an encounter with the Big Bad.
In Disturbing Behavior, Dr. Caldicott's daughter is found in a mental institution, constantly repeating the phrase "Meet the musical little creatures that hide among the flowers."
There Will Be Blood "Get out of here, ghost. Get out of here, ghost. Get out. Get out of here, ghost."
Tie-in media for The Blair Witch Project reveal that Kyle Brody, sole surviving victim of Rustin Parr, was reduced to gibbering insanity later in life, only ever saying "Never given! Never given!" over and over again. Parr himself was also prone to muttering the phrase shortly before his execution.
In Transformers: Revenge of The Fallen, Sam starts babbling while under the influence of a shard of the AllSpark, sometimes repeating himself over and over and over, "KITTEN CALENDAR KITTEN CALENDAR KITTEN CALENDAR..."
Dr. Strangelove "Peace on earth/purity of essence/peace on earth/purity of essence" scribbled everywhere. Also an important clue.
Admiral Beckett in Pirates of the Caribbean: At World's End suffers one of these when he realizes he's lost control of the Flying Dutchman and both it and the Black Pearl are bearing down on his ship. "It's just good business."
"Part of the crew, part of the ship. PART OF THE CREW, PART OF THE SHIP!!"
The Pianist "Why did I do it? Why did I do it? Why did I do it?"
Halina: "She's getting on my nerves. What did she do, for God's sake?"
The animated movie 9: "The source... The source... Go back... to the source..."
Empire Of The Sun: "I can bring everyone back, everyone... I can bring everyone back, everyone..."
The virus in the film Pontypool causes the infected to go mad and repeat phrases. Something gets stuck... gets stuck... stuck... stuck...?
Unusual in that it can actually be counteracted, with difficulty. Rendering the repeated word meaningless breaks its mental hold. Mazzy gets Sydney to replace her chanted mantra of "kill" with "kiss", and they get on the air and try to spout nonsense to all their listeners.
Them!: "Make me a sergeant in charge of the booze! Make me a sergeant in charge of the booze!"
Predator: "I'm gonna have me some fun... I'm gonna have me some fun... I'm gonna have me some fun... I'm gonna have me some fun..."
Marie from High Tension repeats the phrase "I won't let anyone come between us anymore" in a whispering voice over and over when kneeling above her blood-drenched but still living best friend (and secret crush) Alex, whom she spent the movie trying to save from a sadistic rapist/serial killer. The real madness of it comes into play with the knowledge that The killer was an alternate personality of Marie herself, and she was repeating that phrase after Alex stabbed her through the torso with a crowbar.
In Falling Down, the main character spots a man protesting his recent lay off with a sign proclaiming that he has been deemed "not economically viable." The mantra proves contagious, as the main character has also just been laid off.
In A Nightmare on Elm Street 3: Dream Warriors, Kristen threatens an orderly with a scalpel to stop the doctors from sedating her, while weepily reciting the "One, Two, Freddy's coming for you" Ironic Nursery Tune. She's too much of a basket case from sleep deprivation to recall the last line, but Nancy arrives and finishes it for her, soothing the girl enough that she hands over the blade.
In H. P. Lovecraft's novel At the Mountains of Madness, when the nameless Narrator and his colleague Danforth leave the city of the Elder Things in the mountains of Antarctica via airplane, one of them glances over the mountain range and sees... something, which causes him to scream like a madman and begin repeating the phrase "Tekeli-li" over and over again (in reference to the story Arthur Gordon Pym by Edgar Allan Poe, and also used to describe the whistling sound the Elder Things made and which the shoggoth are mimicking). What exactly he sees he never tells to the narrator, except in disjointed phrases such as "Yog-Sothoth", "The Black Pit", "The Elder Pharos", "Proto-Shoggoths" and "The First, the Last and the Immortal".
Also, a bit earlier, when they see the multi-eyed amorphous mass of a Shoggoth and they are running for their lives, an insane Danforth starts singing "South Station Under - Washington Under - Park Street Under - Kendall - Central - Harvard -" and so on, reciting the familiar underground stations between Boston and Cambridge as a monstrous analogy to how the shoggoth emerged from the mists towards them like an underground train emerging from the darkness of a tunnel.
Lloyd has his own Madness mantra a little later, when he's still locked up and so hungry he's contemplating cannibalism. As he's trying to reach for the arm of the guy the next cell over, he has the song "Camptown Races" stuck in his head, and keeps idly singing the one nonsense bit of the chorus, and nothing else, over and over: "Doo-dah...doo-dah..."
And in King's Pet Sematary, Lou Creed becomes fixated on the line "Hey! Ho! Let's Go!" from the Ramones' Blitzkrieg Bop as he becomes more and more unhinged. Stephen King seems to really like this trope.
He included it near the end of his short story "Crouch End", too: after losing (in a very literal sense of that word) her husband to something that lives in Crouch End, the central character takes to crawling to the back of her closet and writing, over and over, "Beware the Goat with a Thousand Young".
Yet another from Stephen King, in Rose Madder, as Norman chases Rosie and Bill into the painting and his Ferdinand the Bull Mask fuses to his head, he takes to repeating "Viva ze bull".
The most unnerving King example may be from his short story The Jaunt. "Longer than you think, Dad! Longer than you think!"
And in the Second Chronicles, Covenant himself with "Don't touch me." But he wasn't really insane, just catatonic, and quoting himself from First Chronicles. This mantra underscored how, as a leper, he was cut off from all human contact. The other mantra from this book was "It isn't catching," to ram home that there was no real reason for everyone to avoid him.
In The Westing Game, a story is told about two boys who went into Westing's mansion. It is mentioned that one boy ran out and he kept repeating "purple waves, purple waves".
At the start of the Anthony Trollope novel An Eye for an Eye, we are introduced to a madwoman who incessantly repeats "An eye for an eye, and a tooth for a tooth. Is that not the law?" The rest of the book is a flashback that explains what made the woman go mad.
In Elantris, this is how residents of the eponymous city can tell when one of them is insane beyond recovery.
In A Tale of Two Cities, an old letter relates the story of a woman who has gone mad with grief and stress, and can only repeat, "My husband, my father, and my brother!... One, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, hush!"
There is also the little old lady in Bleak House who has been driven mad by the Chancery Court's failure to settle her case: "I am expecting a judgment shortly...on the Day of Judgment."
In House of Leaves, Johnny Truants mother is in a mental hospital. Her correspondence to her son reflects this clearly, as she starts repeating certain phrases over and over in her letters. In the Holloway tapes, we hear Holloway chanting, "I'm Holloway Roberts. Born in Menomonie, Wisconsin..."
Although he doesn't say it out loud, Grand Moff Tarkin has one of these for about two seconds at the end of Death Star during a Villainous Breakdown. It went "Unthinkable. Unthinkable - boom." (Since it's the end of a book called Death Star, you can guess where the boom came from).
In John Ajvide Lindqvist's first novel Let The Right One In, one boy who gets locked in a basement with the monster (well, one of them) is found hiding in a corner, reciting the Swedish equivalent of "One Elephant Went Out to Play". By the time people find him, the number of elephants on that spider web is somewhere in the hundreds.
In "The Happening", people affected with the neurotoxin will shout some arbitrary phrase while their brains are being reprogrammed.
In The Wheel of Time Rand al'Thor keeps itemizing all the women for whose deaths he makes himself responsible for. Seeing as he makes himself responsible for the death of everyone even remotely connected to him, commanding hundreds of thousands and fighting a war for the further existence of creation it becomes quite long.
In The Good Soldier,Nancy goes insane because of Leonora's treatment of her and Edward's suicide and can say nothing but a Latin phrase meaning "I believe in an omnipotent God" and the word "shuttlecocks."
In The Great Divorce, two of the souls in Hell have tracked down Napoleon Bonaparte, who can do nothing anymore but pace around chanting "It was Soult's fault. It was Ney's fault. It was Josephine's fault. It was the fault of the English. It was the fault of the Russians."
Also from Theon Greyjoy is "(S)He needs to know (her)his name."
Arya's prayer might fit: "Ser Gregor, Dunsen, Raff the Sweetling. Ser Ilyn, Ser Meryn, Queen Cersei." She's not insane, but it seems to have become a compulsive behavior by the end of the last book.
"No one is who they say they are." Tokyo Year Zero by David Peace is a 400-page Madness Mantra.
In The Nameofthe Wind Master Elodin leads Kvothe through the University's insane asylum; he tries to demonstrate how in over his head Kvothe is by opening one of the soundproof doors. Immediately the hallway fills with incessant screams of "THEY'RE IN ME THEY'RE IN ME THEY'RE IN ME!"
Legends of Lone Wolf: "Tick, tick, tick, tick, You're touched by the colours and the colours stick."
The Ray Bradbury short story "The Long Rain" is about a group of men on the perpetually rainy planet Venus, searching for one of the dry "sun domes" that have been built there. One man recalls that an old friend of his snapped after being on Venus too long, and was found wandering around repeating, "Don't know enough, to come in, outta the rain. Don't know enough, to come in, outta the rain. Don't know enough—"
George R.R. Martin's "The Skin Trade" has a minor example, after P.I. Randi insists (despite strong recommendations against it) on examining the body of a murder suspect who died similarly to her own father. For the rest of the day, the only thing she can say is repetitions of "It was Roy Helander, and he was wearing Joanie's skin."
In Fate Zero, after having her right hand cut off by Maiya to remove the Command Spells she forcibly got from Kayneth, Sola-Ui starts repeating "My right hand... my hand..." all over. These are also part of her Famous Last Words.
A minor character in the Collegium Chronicles is driven insane by Valdemar's vrondi-powered antimagic shield.*
The Healers told his boss to get that man out of Valdemar, but did he listen?
During his last on-page appearance, he's repeating a verse over and over in an apparent attempt to keep the vrondi away from him.
...and all the things that are not there, they flock and fly and stare and stare, and all their eyes are big and bright and burn away the dark of night, and there is nowhere left to hide, they're everywhere, they get inside, and even though they are not there, they're watching watching everywhere, and more and more come every day, oh gods I wish they'd go away, and all the things that are not there, they flock and fly and stare and stare ...
Lampshaded; Caine: Hungry in the dark...HUNGRY IN THE DARK!!!Diana: not this again. Caine: *Snaps out of it* What? Diana: It's one of your greatest hits.
There is one at the end of Alexander Pushkin's short story The Queen Of Spades. Herman thought he gained a secret magic combination of winning cards, but he lost his property in his gamble. He was confined to a mental asylum, constantly murmuring: "Tray, seven, ace! Tray, seven — queen!"
Topher in Dollhouse does this too: "I know what I know."
Certainly puts that Paul Simon song in a new perspective.
Shawn from Psych, assigned to hire Da Chief a nanny, rejected a candidate out of hand because she was writing a single phrase in her notes repeatedly. Neither he nor the audience can tell what the phrase was, but Shawn states that "There's no combination of words that makes that acceptable".
In The Pretender episode "Crazy" Jarod poses as a psychiatric patient and repeats the phrase "Cree craw toad's foot, geese walk barefoot." In a later episode, this is revealed to be a mantra spoken by Edna Raines, a legitimate psychiatric patient. This also qualifies as Arc Words, as Jarod was saying the phrase when he was first brought into the Centre as a little boy in the very first episode.
Badger: "Tear the roof off the sucker! Tear the roof off the sucker!" is the mantra of Clarence Cornice, a six-foot six architect whose short partner Frank Lloyd Wrong insisted on building houses with a six foot ceiling until Cornice became homicidally deranged.
Badger used the phrase in a later episode when feeling homicidal himself.
In American Gothic, Merlyn's Madness Mantra was "Someone's at the door". These were her last words as a sane individual. Someone was at the door, and when he came in, he raped Merlyn's mother in front of her.
This same mantra is then used many times over as a Catch Phrase for the series, but is especially delicious when employed by Merlyn's ghost to haunt the coroner who lies about her cause of death to protect his family from Buck (complete with the disturbing tape-recording that alternates between extremely fast and high-pitched, and extremely slow and garbled), and later to taunt Buck himself.
Night Visions had "Now he's coming through the woods, now he's coming through the yard, now he's coming up the stairs..."
One episode of Law & Order had a psychiatrist whose peace mantra became his then ex-patient, now wife, now killer's Madness Mantra: "I am a rock in a sea of chaos, I am a rock in a sea of chaos..." after she learned that the underaged girl he lusted after was actually her under a different name.
In Season 7 of CSI: Crime Scene Investigation: Crime Scene Investigation, when the "Miniature Killer" is finally brought in for questioning, she begins rocking back and forth, reciting "I Have a Pain in My Sawdust"
Earlier Nick Stokes's stalker Nigel Crane from the aptly titled episode "Stalker" is reduced to repeating "I am one, who am I? I am one, who am I?" after being caught.
A Season 1 episode of CSI: NY shows Mac laboriously recovering a document from a damaged hard drive that simply says "Three generations are enough" over and over again.
Kids in the Hall does a pretty good job using this for comedy. "Can't wash the car without a whole lotta milka..."
"Never put salt in your eyes. Never put salt in your eyes. Never never never put salt in your eyes. Your eyes. PUT SALT IN YOUR EYES."
Wiseguy. "Only the toes, knows." Favourite saying of mad international Arms Dealer Mel Profitt, who shot up drugs between his toes.
In The Drew Carey Show, the show regulars read through the day planner of an insane ex-coworker who has started emulating Drew.
"Be more like Drew. Be more like Drew. Be more like Drew. Be Drew."
One interesting episode of Criminal Minds had the star played by Frankie Muniz (of Malcolm in the Middle fame), whose Madness Mantra was his now-deceased girlfriend's voicemail message, which included "I'm out living my life. Leave a message!" At the end of the episode he's in a padded room with his cell phone just listening to that over and over again, as it was all he had left of her.
Er, not quite. He was still calling her, because he had once again forgotten she had died. Throughout the episode he was trying to get a hold of her, even though he was with her when she was murdered. The FBI reminding him of that didn't change the fact that he was still suffering a psychotic break.
The Master from Doctor Who has his own musical Madness Mantra, the sound of drums (tap tap tap tap, tap tap tap tap, tap tap tap tap, tap tap tap tap)
The episode "Silence In the Library" is full of these. All who have been killed by the shadows repeat their last phrases over and over again, "Hey, who turned out the lights? Hey, who turned out the lights?" And then there's the terrifying " Donna Noble has left the library. Donna Noble has been saved."
"Are you my mummy?" from "The Empty Child"/"The Doctor Dances." At one point the Creepy Child possesses a typewriter and types it over and over; in the podcast for the episode, Steven Moffat claims not to remember any similar scene from The Shining.
"I did my duty for Queen and country." Though somewhat inverted because Yvonne Hartman's Heroic BSOD actually helped her retain some of her personality and she ended up killing a patrol of fellow Cybermen.
In "The Doctor's Wife", the Rory illusion created by House to mess with Amy's head seems to have acquired a madness mantra after spending millennia separated from Amy in the corridors of the TARDIS. Initially, Amy encounters a version of Rory who has aged two thousand years, and he keeps repeating "Every night, they come for me. They hurt me..." Later, Amy discovers a corridor containing Rory's decayed corpse. The walls of the corridor are covered in graffiti in black and red: "Hate Amy, Kill Amy, Die Amy, Hate Amy, Kill Amy, Die Amy..." Personally this troper is trying hard not to think of what Rory used for ink. It's chilling.
Again (only real this time) with Rory in "The Girl Who Waited". While Older!Amy is telling him not to let her in, he can only whisper "I'm so so sorry" over and over again.
In "The God Complex", people who find their rooms (and therefore their greatest fears) eventually begin to pray to the monster stalking the halls. Praise him. Praise him. Praise him!
One from the audios: the Eighth Doctor, having spent two and a half episodes on the edge of sanity, falls off it. "Zagreus sits inside your head," BANG! "Zagreus lives among the dead!" BANG! "Zagreus sees you in your bed—" BANG!
Near the end of Midnight, the Doctor is so rattled by what just happened that he can't do anything but gasp "It's gone. It's gone." for several lines, and is silent for some time after he manages to stop.
Red Dwarf: During one of his fourteen failed attempts to pass the astro-navigation exam necessary to become an officer of the Space Corps, Rimmer suffered a nervous breakdown and ended up writing "I am a fish" 400 times, then did a funny little dance and fainted.
In a nonverbal example at the end of season 4, President Clarke commits suicide, leaving behind a note that just read "THE ASCENSION OF THE ORDINARY MAN THE ASCENSION OF THE ORDINARY MAN THE ASCENSION OF THE ORDINARY MAN...". There's a twist in this example, each line has a letter circled, and the circled letters spell "scorched earth"—Clarke had activated the Global Orbital Defense satellites and set them to fire on the Earth and wipe out every man, woman, and child on the entire planet. The Army of Light's fleet took them all out just in time.
"The Corps is the Mother. The Corps is the Father. The Corps is the Mother. The Corps is the Father..."
In Thirdspace after the artifact is found Lyta Alexander writes "There is Danger, Remember" on all available surfaces in her quarters and constantly repeats it under her breath going to the control room.
A scene in Screenwipe has an office worker who keeps typing "I am a flower in a dustbin I am a flower in a dustbin I am a flower in a dustbin I am a flower in a dustbin I am a flower in a dustbin I in a dustbin" on his computer while "In The Air Tonight" plays hauntingly in the background.
Particularly in the album version, during Monty Python's sketch of "The Travel Agent", a customer endlessly rambles about his past trips around the world. This gets to be so unbearable that the travel agent just keeps screaming "SHUT UP! SHUT UP! SHUT UP!"
"...bleedin' Watney's Red Barrel..."
In the Smallville episode "Gemini", a hospitalized woman continually mutters in gibberish. Bizarro listens to her and explains that she is speaking in Kryptonian. He translates it, and says she is just saying ones and zeros, and it becomes binary code. When the binary code is translated, it becomes "Error: Reboot" over and over again. Brainiac had jacked the woman's brain.
Mantrid: I'VE DESTROYED AN UNIVERSE! I'VE DESTROYED AN UNIVERSE! I'VE DESTROYED AN UNIVERSE!!!
In Angel the psychotic vampire slayer Dana had several of these, one of which consisted of information on vampire killing she'd never been told.
On Dexter, Angel is hospitalized and has to spend the night next to a patient who was brought over from a mental institution who keeps repeating the words "She knows". He finally snaps and yells that if 'she' knows, then the guy's yapping about it isn't gonna fix anything.
In an early M*A*S*H episode, the storyline revolves around Henry being stalked by a rather unstable, wounded soldier. The soldier desperately wants to return home, worried that his wife had been cheating on him, but was furious at being denied leave on account of the extent of his injuries. Eventually, it gets to the point where a running, unmanned jeep comes crashing through Henry's tent, leaving him so shocked that he repeats over and over "Jeep. Tent. Boom."
In Dad's Army, when Jones is overcome by terror he starts shouting 'DON'T PANIC!', in increasingly panicked tones.
Happens twice in the Star Trek: The Original Series episode "The Changeling". Once with Spock saying "Sterilize" over and over again after a mind meld gone wrong with the probe NOMAD, the second with NOMAD after Kirk gives it a Logic Bomb, causing the probe to repeatedly shout "Error!".
From the Mad Hatter, naturally, in Once Upon a Time, who kept saying "Get it to work! Get it to work!" as he's making thousands of hats in Wonderland in a hopeless effort to try to get back home to his daughter and thus revealing how he got his name and how he ended up a permanent character in Wonderland.
The Governor's notebook on The Walking Dead. Apparently when he lost his daughter he went a little nuts and stopped taking careful notes about his settlement and started filling the notebook with page after page of slash marks.
Weird Al Yankovic's song "Dare to be Stupid". Where he incites the audience to "Dare to be stupid dare to be stupid dare to be stupid", citing ridiculous examples such as microwaving your head, to define "stupid".
Kylie Minogue's Love at first sight.... it was love at it was love it was love it was love it was love at first sight. etc etc. A song about a love struck light headed Kylie as she staggers back and forth in a love struck delirium on another planet, complete with futuristic dancers (aliens, clones, robotic men). Kylie's song "Wow" composed mainly of chanting "wow. wow. wow. wow. wow. wow. wow. wow. wow.* infinity).
Napoleon XIV, from side to side and straight down the middle.
"They're coming to take me away - ha-ha, hee-hee, ho-ho..."
They're trying to drive me sane...hee-hee...they're trying to drive me sane...ho-ho...they're trying to drive me sane...ha-haa...they're trying to drive me sane!...hee-hee!...they're trying to drive me sane!...ho-ho!...THEY'RE TRYING TO DRIVE ME SANE!...HA-HAAAA!...THEY'RE TRYING TO DRIVE ME SANE!!!"
"Bodies" by Drowning Pool: "Let the bodies hit the floor, let the bodies hit the floor..." "One - nothing wrong with me, two - nothing wrong with me, three - ..." "One - something's got to give, two - something's got to give, three - ..."
"All Over Me": "All over me! ALL OVER ME! All over me! All over me. All over me! ALL OVER ME! All over me! All over me."
"Psycho Killer", by Talking Heads: "Psycho Killer! Qu'est-ce que c'est? Fa-fa-fa-FAH-fa-fa-fa-fa-FA-FA better, run, run; run, run, runaway."
The chorus of the song "They're Coming To Take Me Away", as in the page quote.
"AKA Driver" by They Might Be Giants. "It just a full day's drive awaaaaaay. It's just a full day's drive awaaaaaaaaaaay..."
Gilbert and Sullivan; though there are many examples, the quartet from The Gondoliers featuring the Duke and his entourage's entry stands out. "And... if... ever ever ever they get back to Spain, they will never never never cross the sea again; they will never never never never never never never never never never never cross the sea again - they will never never never never never never never never never never never cross the sea again!" - And they sing that chorus twice!
"Aenema" uses this too: "Learn to swim, learn to swim, learn to swim, learn to swim..."
"Schism":"I know the pieces fit, I know the pieces fit, I know the pieces fit, I know the pieces fit..."
The song "He Knows, You Know" by Marillion has the word "problems" repeated many times, with the last one shouted - "Problems,problems,problems,problems,PROOOBLEEEEEMS!!". This might have something to do with the lyrics being about a man going insane, and committing suicide in a bathroom. The song also ends with a phone call, with the man shouting to a woman at the other end "Don't give me your problems!" and slamming the phone down.
The song "Echoplex" by Nine Inch Nails ends with Trent Reznor repeating "You will never, ever, ever, ever, get to me in here. You will never, ever, ever, ever, get to me in here...."
"The Becoming" also qualifies: "It won't give up. It wants me dead. Goddamn this noise inside my head..."
"Piggy": "Nothing can stop me now!". Not exactly a conventional example, but it is an example of the narrator losing his grip on reality. A variation on this one also shows up in "Ruiner".
"Big Man With A Gun" qualifies as well: "Me and my fucking gun, me and my fucking gun, me and my fucking gun..."
The ending of Motel of the White Locust by Glassjaw: "Pack your shit and leave and take my memories of her with you..." It then concludes with the variation: "Pack your shit and leave and take her fucking with you."
"I've lost my mind, I've lost my mind, I've lost my mind" in Disturbed's Perfect Insanity.
In The Decemberists's "The Mariner's Revenge," a man constantly hears his mother's final words, begging him to take vengeance on the man who left them destitute: "Find him! Bind him! Tie him to a pole and break his fingers to splinters! Drag him to a hole until he wakes up, naked, clawing at the ceiling of his grave!" In the end, it's implied that the man whispers the mantra into his prey's ear, but the song only plays an increasingly manic, instrumental version of the mantra's tune, implying that he's doing some pretty unspeakable things.
Pet Shop Boys' "I Want To Wake Up" has the title line repeated increasingly desperately through the song as it becomes clearer the narrator is going crazy from unrequited love: "Now, I want to wake up. How I want to wake up. I, I want to wake up, I want to wake up, wake up, wake up with you..."
"I'm Sorry, I'm Sorry" could fit as well, going by her staring expression at the end of the video.
American Music Club's "In My Role as The Most Hated Singer in the Local Underground Music Scene":
Oh God I love you
Oh God I love you
I should have killed you when I had the chance
Radiohead has a lot of repeated phrases that can be interpreted this way.
From Kid A, special mention goes to "How to Disappear Completely" ("I'm not here, this isn't happening... I'm not here...") because the line comes from a way Thom Yorke coped with the pressures of touring (so it overlaps with Survival Mantra). And "Everything in Its Right Place" is practically built out of them, and also inspired by breaking down on tour.
Also "Karma Police": "For a minute there, I lost myself, I lost myself..."
"2+2=5": "You have not been paying attention, paying attention, paying attention, paying attention..."
"Sit Down Stand Up" is a far more clear-cut example: "The raindrops. The raindrops. The raindrops. The raindrops. The raindrops. The raindrops. The raindrops..." As the music gets ever more frantic.
"Three Peaches": I'm so happy, I'm so happy that you didn't die...
"Rubby Bulbs": Beautiful babies / Are filled with angels!
"Sailing Through": You are a liar, you are a liar, you are a liar, you are a liar and YOU ARE A LIE!!!
Nick Cave knows this trope well. "How much longer?" from Loverman is one example.
The World/Inferno Friendship Society turns the end of "Canonize Philip K. Dick, OK?" into one of these, sung as a round: "You can't change the system from within the system changes you, you can't change the system from within the system changes you, you can't change the system from within the system changes you ... and that should make you PANIC!"
Invoked in King Crimson's "Indiscipline": "I REPEAT MYSELF WHEN I'M DISTRESSED! I REPEAT MYSELF WHEN I'M DISTRESSED! I REPEAT MYSELF WHEN I'M DISTRESSED!"
Pre-Crimson group Giles, Giles & Fripp also did one with "Just George", where, in between the songs in the second half of the album, the band would repeat "I know a man and his name is George" in various ways.
In "Thela Hun Jinjeet" Adrian Belew, who had just been assaulted by gang members on his way to the studio, repeats "This is a dangerous place" several times.
A good chunk of Frank Zappa's "Help, I'm A Rock" has the band chanting the title. Helps that the title of its parent album is Freak Out!.
Nirvana's "Lithium": "I like it, I'm not gonna crack. I miss you, I'm not gonna crack. I love you, I'm not gonna crack. I killed you, I'm not gonna crack!"
In Radical Face's "Kin", after Virgil gets a blood transfusion he starts to hear ghosts and slowly loses his mind: "I hear them al the time, I hear them all the time, I hear them all the time".
Disturbed does this in Perfect Insanity. I've Lost My Mind I've Lost My Mind I've Lost My Mind I've Lost My Mind I've Lost My Mind...
Closing track "The Apostate" throws a few more into the mix, including variations on "get out of my mind", "ladder to god", and "we are blessed."
Edge of Dawn - Falling: "Destroy as much as you can, you're not an angry man / You're lost, you're lost, you're simply lost / You're lost, you're lost, you're lost [...] But you're lost, you're only lost"
From the fluff book Xenology, containing autopsies and analysis of various xeno species and artifacts: "The Metal Lives. The Metal Lives. The Metal Lives. The Metal Lives.The Metal Lives The Metal Lives The Metal Lives The Metal Lives..."
BLOOD FOR THE BLOOD GOD! SKULLS FOR THE SKULL THRONE!
Transience of flesh; purity of form...Transience of flesh; purity of form...Transience of flesh; purity of form... (from a certain mutation cult)
Chaos does this a lot (it's all in the name, really). Other examples include "SANITY IS FOR THE WEAK!" and "IT IS AS THOUGH A THOUSAND MOUTHS CRY OUT IN PAIN!" and the above-mentioned BLOOD FOR THE BLOOD GOD!!. And yes, upper case and exclamation marks are necessary in all examples.
The Apocalyptic Log that opens All Flesh Must Be Eaten has a scientist, undergoing transformation into a zombie, muttering in his last log before complete zombification "God, why" about a dozen times.
Theater & Stage
Sweeney Todd has an example which actually takes place in an asylum, with the inmates singing "Sweeney" over and over again, until Johanna kills the owner of the asylum, when they screech and stop the chanting.
Oofty Goofty, a sideshow performer from the 19th century American West, started out his career as a costumed "Wild Man of Borneo" act, in which he constantly babbled the nonsense-phrase that became his stage name.
Next To Normal has the song It's Gonna Be Good (reprise), where Diana repeats the phrase "what was his name?" in wanting to know her dead son's name, and Dan repeating "gonna be good" to convince Diana going back for therapy sessions.
At the conclusion of Henrik Ibsen's Ghosts, Oswald, who was infected with syphilis in utero by his philandering father, succumbs to dementia and stares blankly into space repeating the words "The sun"
In Le Roi Jones' play Dutchman, the lead woman, Lula, starts repeating the conclusion of a story told by her co-star: "And that's how the blues were born" several times before completely flipping out, stabbing him, and pushing him out of the subway car they're both riding.
The Merchant of Venice: Shylock's speech pattern is very repetitive, even at the beginning. This becomes nightmarish later when he becomes intent on killing Antonio:
I'll have my bond, speak not against my bond:
I have sworn an oath that I will have my bond...
I'll have my bond; I will not hear thee speak:
I'll have my bond, and therefore speak no more...
I'll have no speaking: I will have my bond.
Macbeth: Lady Macbeth chants "Out out, damned spot". It is stated that she has been doing this for some days.
System Shock 2. The Hybrids, when not attacking, piteously ponder "We are? We are?" and "What... happened to me?", and when they attack, they either apologetically shout "I'm sorry! Run! RUN!" or growl "You are not one of us!" or "You cannot see!" The Cyborg Midwives are even creepier, walking around talking about caring for "the little ones".
In Fable II in the Terry's Cotta area, when you find Terry's Final Diary, the last words were "They watch over me. They watch me. They watch me. They watch me...", which indicates that Terry had gotten insane from the unending stare from the Knights.
Lux Pain is full of these- the Shinen of those infected with Silent tend to repeat phrases like "I'll kill you" and "This is fun" over... and over... and over...
If left idle, Arakune from BlazBlue will start babbling "I'm different, I'm different, I'm different" in the middle of a battle.
Eternal Darkness: Sanity's Requiem could, potentially, develop a Madness Mantra. Let the true magnitude of what they're fighting take hold, and the various characters will begin to assert that "This... isn't... really... happening!" (Sadly, that was optimistic.)
Usually. Sometimes, they weren't just surrounded by horrifying things; they were surrounded and hallucinating on top of it.
Then there's "May the rats eat your eyes! The darkness comes..."
Treasure Of The Rudras. You can use a Mantra (Custom Made spell based on how it is typed; inscribed) to actually invoke madness status on your characters or enemies.
Half-Life 2. "...they're always departing but they never arrive... and the ones that do arrive, they-they never leave... you never see them go... they're always full... no one ever gets on... but they're always... they're always departing but they never arrive..."
Max Payne: The Arc Words of the first game, "the flesh of fallen angels," are repeated by certain V-crazed junkies as well as the psychotic Act I boss Jack Lupino. The phrase is also used by "the pink flamingo" in the in-game TV show "Address Unknown", although it's stated in a creepy distorted voice that's hard to make out (a tribute to the backwards talking in Twin Peaks).
Also in the "Address Unknown" show: Mirrors are more fun than television.
The World Ends With You: "To right the countless wrongs of our day, we shine this light of true redemption, that this place may become as paradise. What a wonderful world such would be." Repeated by anyone wearing a red skull pin, except Neku. By the end of the game, it's affected everyone (including the reapers) in Shibuya except for Kitaniji, Neku, Beat, Joshua, Konishi and Sho... and that one reaper who missed the emergency meeting.
If you replay and seek out all the hidden item boxes, Neku finds out that the decals allowing the players to interact with living people in shops also blocks the effects of the Red Skull pin, heavily implying that it's the Composer's power (which is behind the Player Pin and the decals) that blocks the madness.
A possible subconscious example: during the dream in which he encounters The Outsider, Corvo finds a note next to the body of the the Empress. The note says: YOU CANNOT SAVE HER YOU CANNOT SAVE HER YOU CANNOT SAVE HER YOU CANNOT SAVE HER over and over.
In the city of Theramore in World of Warcraft, there's an NPC, James Hyal (or Smiling Jim). He was the owner of the Shady Rest Inn, before it was burned down by the Grimtotem Tauren, and constantly recites a song written in his honor: "He'll bring you mead, he'll bring you beer; A grinning face from ear to ear; He's served us all from year to year; We call him Smiling Jim." Besides the occasional laugh, that's all he ever says.
When he is listing the colours he thinks of in the book, he lists various colours with RED being the only one capitalized, than you flip to the next page to be greeted with: BLACKBLACKBLACKBLACKBLACKBLACKBLACKBLACKBLACKBLACK!!!!
Another diary in Oblivion is written by a vampire who's slowly going crazy from bloodthirst. The last page goes "Food blood blood blood blood I need it I need blood need blood"
In Persona 2: Eternal Punishment, Joker uses the word "voices" in this manner — some of his battle taunts are just shouting "voices", and during the point of his most intense breakdown, he just repeats "voices" over and over again for nearly a dialogue box's worth of speech. This is because he's Tatsuya Sudou, a.k.a. King Leo from the previous Persona 2: Innocent Sin, and the leader of the previous Joker's Masquerade Executives. He hears voices — actually Nyarlathotep — that tell him of the previous world and his role in it, causing him to take up the mantle of Joker and try to push events to repeat themselves... with the side effect of making the already deranged Sudou even crazier.
Baldur's Gate: "TIAX RULES ALL!", "Back! Bad dog! Play dead!", and "Many, many pretties... piled high beyond the sky!"
There's also a minor character named Mad Arcand who peppers his speech with "(wertle wertle woo)" and asks you to go and get something from a pirate ship, admonishing you not to wear it or "you'll wertle too." It's a cursed Ring of Folly.
There's also the Elven Wizard one originally met on the Wolfwere island, but now held in Spellhold. Almost everything he says ends in, or gets interrupted by him shouting "BAD DOGGIE WEREWOLVES"
Baroque gets extra irony points for having the Absolute God chant "Don't go crazy Don't go crazy Don't go crazy Don't go crazy". For added effect, the subtitle for each instance was placed at a random point on the screen. Turns out she was actually telling the protagonist not to go crazy like her.
A mental hospital patient although they might have been a hallucination in Phantasmagoria 2 had a habit of chanting "Disco dance! Disco dance! Disco dance!". The result was... less than terrifying.
He says several more when clicked on repeatedly, such as "Pizza, pizza! PIZZA!" "There's my taco salad!" "Froot Loops and Cheerios!" "Harry Belafonte!" or "Everybody in the POOOOOOOOOOOL!"
And the girl repeatedly chanting "Sick and wrong...sick and wrong!"
Practically every NPC in BioShock that is capable of speech does this, from the Splicers' "Father! Why have you forsaken me?" and "What more can I give you, Mr. Ryan?" to the Little Sisters' "Look, Mr. B, an angel!" to the more unique ones like "Aesthetics are a moral imperative" and "I CAN'T TAKE THE EARS OFF!" The Splicers and Little Sisters have dozens of them.
Them singing "Jesus loves me this I know", since Christianity was supposed to be banned in Rapture, and there are smugglers crates full of nothing but tons and tons of Bibles.
Silent Hill 2 has a written one early on: the phrase "Run away!" written over and over again on a sheet of notepaper left on the ground.
In the horror/adventure/drama game Fragile Dreams, the player character Seto enters a trashed room filled with boxes and other post-apocalyptic junk towards the end of the game. For those using one of the regular flashlights, there is nothing remotely disconcerting about this room. However, if, like this troper, you were using the flashlight that allows you to see hidden messages written on the wall, you will suddenly enter a room where every surface has "I don't want to die! I don't want to die! I don't want to die!" scribbled over it in an increasingly desperate hand. If you scare easily, do yourself a favor and don't enter the room with that flashlight.
Through the games, we see the Awakening - the first summoning - of four of the eight avatars. Each one is accompanied by the summoner's total mental collapse and their own distinctive mantra, whether it's Atoli yelling Sakaki's name, or Yata just screaming "No!"
Though the real significance of it isn't revealed until the game's end, Travis Touchdown has a nice inner monologue during the first boss fight of No More Heroes which ends with the repetition of the phrase "Can't find the exit" a good twenty times.
Myst III: Exile. If you trap Saavedro behind the shields in Narayan (which you have to do to finish the game with the Good Plus Ending), he first looks up at you, mumbles to himself about how stupid it was to trust you, then starts screaming "NO" overand overand overand over... And then later, if you try to get the MacGuffin from him, he pleads for his release and starts doing it again.
Rule of Rose has, right at the end, one of these. Stray Dog's "I'm sorry, Joshua," line during the last boss fight seems to fit, at least.
Kefka, in the Bowdlerized version during the flying continent Sequence: Hate Hate Hate Hate Hate
The translation in the GBA version subverts this, as it turns out to be more along the lines of Angrish.
And in Dissidia: Final Fantasy his madness mantra seems to have become "Destroy" and "Destruction". This is more or less stated outright and explained during Kefka's final moments where it is revealed that he is unable to find any meaning in life due to, and beyond, all things' inevitable destruction.
In Final Fantasy VIII, what appears to be random letters that's been overpowering the television airwaves for the last eighteen years is actually a Bilingual Bonus mantra in English if you look carefully: "BRING ME BACK THERE I AM ALIVE HERE" and "I'LL NEVER LET YOU FORGET ABOUT ME." The interference is caused by a powerful magic-jamming device in orbit, imprisoning the evil sorceress Adel for these last eighteen years.
Fatal Frame 4: "It hurts!!! So much fun!!/It hurts, the fun much hurts/The surgery is fun, it hurts/The surgery fun/Fun nn, it hurts ss/Hate fun nnn/Hurts ss/Ssss..."
In Halo 3, after Guilty Spark finally completely loses it, all he can do (aside from firing his Frickin' Laser Beams) is repeat "UNACCEPTABLE!!"
One of the terminals in Halo Anniversary Edition shows a record of Captain Keyes being absorbed into the the FloodGravemindProtoform from Keyes's point of view. Believing that he's being tortured by the Covenant and attempting to fight back as he begins to forget who he is, he begins chanting the information on his dog tag (which, consequentially, is both his identity and the only information soldiers are allowed to reveal when being interrogated by the enemy). Its pretty disturbing, especially since it is not what you expect from the terminals.
The numbers of Call of Duty: Black Ops, which can be heard playing incessantly at several points in the game. Except that the person doing it isn't insane and he's not saying them, He's been brainwashed into becoming a Soviet sleeper agent, and the numbers are a Chekhov's Gun.
In Paper Mario: The Thousand-Year Door, should you attempt to cheat at Lucky the Bob-omb's once-a-day lottery drawing by changing your system's clock, he'll be so disturbed by the fact that he'll go through about six different madness mantras and almost blow himself up in the process before expressing his irritation in a coherent fashion and requiring you to purchase a new lottery number for five times the original price.
"The emitters made us immortal...EROS makes us all-knowing...Typelog makes our thoughts omnipresent... Immortal, all-knowing, omnipresent...immortal, all-knowing, omnipresent...immortal, all-knowing, omnipresent..."
In Sluggy Freelance, when Oasis (who qualifies as Ax Crazy even in the best of mental states) finds out about what Zoe looks like, she goes into a frightening Yandere persona that repeats her Pretentious Latin Motto, "Nosce te ipsum". The irony of her situation ("Know thyself" is the translation, when Oasis has no idea what she is) finally halts her rampage when she realizes it.
Homestuck: PLEASE TELL ME THAT'S JUST GRUB SAUCE. PLEASE JUST BE GRUB SAUCE PLEASE JUST BE GRUB SAUCE PLEASE JUST BE GRUB SAUCE. HAHA, OK, MAKE-BELIEVE TIME IS OVER! OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD OH GOD
One hentai series online has a demon-domination-fetish-incarnate called Talon Talonov, who enslaves his thralls by either having one of his slaves bugger them up the ass while chanting "Talon Dominus, Talon Dominus" or by doing this himself with his four-foot-long flexible penis-tail.
Survival of the Fittest v4 character Kris Hartmann has, with variation, "Voice. Jump. Spin. Squeeze. Bang. Dead." She never actually says it, but it comes up in her thoughts frequently, starting from her Accidental Murder of Reika Ishida.
Nan Quest has one (potentially a few) of these in the journal found in the chapel area.
"for the love of god"
"into the fire into the fire into the fire into the fire"
FUCK YOU BEN I'M NOT TALKING TO YOU
In episode 7 of Sex House, Tara gets one while under the influence of the "cloudy drink": "Cloudy drink kills frog!" Creepily enough, she's even seen writing and rewriting it obsessively on a piece of paper as she struggles to remember to tell her fellow housemates.
"Lisa's First Word": The classic mantra, "Can't sleep, clown will eat me," which a shaken 3-year-old Bart says over and over after the first night in his new "clown" bed. Bart had coveted a Krusty the Clown bed, but Homer – unable to afford one – decides to make one himself. Homer's poor handicraft skills result in a deformed, looming, Monster Clown, which scares Bart to the point he is unable to fall asleep.
They also had to parody the Shining example too.
Homer: No TV and no beer make Homer... something something... Marge: Go crazy? Homer: Don't mind if I do! A-woolagoolawoola!
Just prior to this the trope has already been subverted ("Feelin' fine.") and then twisted right back around on itself like a twisty-tie.
And a Continuity Nod when they go through an actual mental ward and see a certain film critic in the background...
Critic: "It STINKS! It STINKS! It STINKS! It STINKS!"
"Moe, Moe, Moe, Moe..."
One of Bart's earlier babysitters never quite recovered from the encounter.
Sitter: [while sitting blank-faced in a rocking chair] Put it down, Bart. Bart, put it down. Put it down, Bart.
In "Kamp Krusty", when Bart has suffered at Kamp Krusty without any appearance of Krusty the Clown:
Bart: Don't worry, Krusty will come, Krusty is coming, Krusty is coming...
"The Simpsons are going to Florida" episode began with Homer having a breakdown when he realized he will die in 3 years. He is reduced to saying "CAN'T SLEEP, GONNA DIE" over and over.
After Homer breaks out of jail on a book cart:
Homer Must kill Moe... Whee! Must kill Moe... Whee!
In South Park, when Butters' mother discovered that his father was having sex with random men, she repeatedly repainted the house while muttering "Paint... everything clean... everything new..."
When Stan's mother started finding dead people in her son's room, she blamed him, although it was really his evil goldfish. Eager to cover up for her murderous but still beloved boy she dragged the corpses to bury them in the backyard while chanting "You're such a good boy...mommy will protect you..."
"Second verse same as the first, dreidel dreidel dreidel, I made you out of clay..."
Doctor Destiny in the Justice League TV show was stuck humming Frčre Jacques while catatonic after injecting himself with a sedative while fighting Batman, who was humming the song to keep Doctor Destiny from influencing his mind.
"I'll take the chicken. DESTROY US ALL! DESTROY US ALL! DESTROY US ALL!"
At the end of the Metalocalypse episode "Snakes n' Barrels", it's revealed that Pickles' old bandmates create the most brutal album ever with their psychotic rantings, one of which includes the constant "I'm a chicken! I'm a chicken! I think I'm a chicken! I'm a chicken! I'm a chicken! I'm a chicken! I believe I'm a chicken!"
In much-loved animated series Recess, TJ is subjected to Ms. Finster's newest punishment: The Box. At first, he laughs at it. It is just four chalk lines on the ground. No big deal. As he spends more time in "The Box", he begins pacing angrily, starts shouting and "banging" on the nonexistent walls, and then starts to hallucinate that The Box is sinking into the ground. It goes From Bad to Worse when Ms. Finster eventually finds TJ in the fetal position, whispering to himself "This old man...he played two...he played knick-knack on my shoe..."
Winnie the Pooh: I will not be brave I will not be brave I will not be brave...
Danger Mouse: The episode "Ants, Tress And Whoops-A-Daisy" had DM falling into a temple looking for Penfold and running into a group of snakes who have adapted a cult of the 1960s, chanting "Peace and love" over and over. When DM gives an off-handed "Good grief," the snakes adapt "Good grief" as their new mantra.
The Marvelous Misadventures Of Flapjack: In "Fastest Man Alive", K'nuckles goes crazy after being constantly arrested by a constable on a bicycle. He curls up in a ball and is only able to impersonate the bike's bell, going "Ching. Ching. Ching".
CBS anchorman Dan Rather was attacked on Park Avenue in Manhattan by two unknown assailants, one of whom kept repeating (according to Rather's own account) "Kenneth, what is the frequency?" Through Memetic Mutation and a certain R.E.M. song, everyone remembers the phrase as "What's the frequency, Kenneth?"
There is a novel by Spider Robinson that has this as its punchline. It actually makes a certain sense in context. It's "Lady Slings the Booze" Kenneth is a Rather lookalike; the frequency will trigger nuclear devices hidden in major cities, and the two assailants are Soviet agents.
For clarification, the attacker was later discovered to be a paranoid schizophrenic, who thought the media were beaming signals into his mind and that if he found the right frequency he could block the signals.
Dane: ...and then as you're crying, what happens is that it starts to feel good... and what you do is that you latch on to one phrase that you just repeat over and over again; just something that means something to you, like, "I DID MY BEST! I DID MY BEST!"
Autistic people are also prone to stimming: repeated hand movements, checks, and various other body patterns. Some people have the exact same pattern all their life (for example, a specific order for tapping one's fingers on a table). It's a madness mantra without words - though for most people it's just very soothing.
Repeating mantras and stimming are both relatively common byproducts of catatonia.