When a nice, normal character suddenly goes into a rage, you've hit his Berserk Button.
Rugaard from E. E. Knight's Age of Fire series hates being called by any derogatory nickname, and finally snaps when called "Batty" to his face by one of his fellow trainees in the Drakwatch, turning what started off as an ordinary brawl into an Unstoppable Rage as he takes on all three of his bunk-mates at once. Then again, it's understandable when you consider the fact he was without a name as a hatchling and as The Unfavouritewas flat out told by his father he didn't need or deserve one.
Whenever Sunny does something that resembles her maternal grandmother in Akata Witch, Sunny's father takes it very, very badly.
In Animorphs, do not torture Tobias or Rachel will personally rip you apart with her grizzly paws. Only Tobias's pleading saved Taylor.
Best not to insult Andalites around Ax...his arrogance will start to come out. Also don't compare Andalite technology to Yeerk technology.
Claiming to be an Andalite bandit around Visser Three will probably get you missing some body parts very soon. Ditto with just failing him in general.
Marco's is hurting his mother or going after his dad...he would have killed Visser One long ago if he could have.
Ditto with Jake and his family. He really wanted to kill Tom's Yeerk way sooner but it wasn't possible.
Along the same lines, he had a major verbal freakout when he was worried about Tom and someone accidentally referred to Tom's Yeerk by Tom's name.
And Cassie-do not be an animal abuser around her.
Tobias-Be nice to Rachel or it won't be pretty. Also, be nice to hawks. He went postal on the used car guy who had a hawk mascot in one of the early books. He also doesn't take kindly to bullies like the ones who were hassling Erek. He dive-bombed them at least once.
Never, and I mean NEVER get in Ax's way if he wants the delicious and narcotic food he loves SO much...cinnamon buns.
Butler in Artemis Fowl. He's not exactly a gentle giant to start, but go ahead — hurt Artemis, hit him, touch him, vaguely insult him... he's only a weapons expert and a 7 foot tall, 200 or 300 pound, pure muscle man who, like his family has for generations, spent his entire life preparing to be Artemis's bodyguard, and who has barely ever been out of yelling range since he started serving as such by guarding his hospital nursery... yeah, go ahead, just try it.
In A Song of Ice and Fire, do not harm anyone Daenerys Targaryen considers under her protection. This is a rather large number of people. Hurt any of them, and you will die screaming. Also, just being a slaver in her general vicinity is bad for your health.
Craster reacts extremely poorly to the suggestion that he may be illegitimate: "WHO CALLS ME BASTARD?"
If you dare mention the fact that he isn't a lord to "Lord" Vargo Hoat, or, heaven help you, mock his thpeeth impediment.
Like Craster, Ramsay does not react well to any mention of his low birth. Just using the word "bastard" or "Snow" in his presence will likely lose you the skin on your face, if he's in a good mood.
Eddard Stark doesn't enjoy killing people, and normally sees personally executing criminals as a grim but necessary duty. He really hates slavers though. As a result, Jorah Mormont is the one person Eddard Stark would kill with relish.
Barak and later his son in The Belgariad, will transform into bears whenever Garion or his son is threatened, and will rip whatever is threatening their charges to shreds. Barak's son had to be chained to a ship's mast because he went berserk in the middle of the ocean... when Garion and his son were several hundred miles away. You do not mess around with Garion's family, because if he doesn't get you, his grandfather and aunt will.
In The Bible, St. Paul's Berserk Button was the belief that Gentile converts had to keep rules concerning kosher and circumcision. He made a big stink about this because, well, you know...
In regards to Jesus, one thing that got Him ticked off was the merchants making His temple a den of robbers and thieves instead of a temple of worship. Cue to Jesus flipping off the tables and tries whipping the merchants while they run away.
While God Himself has a lot of things that can make Him very furious to the point of dishing out Disproportionate Retributions (the things being sin in general, mind you), one particular one was when all of the Israelites decided to make themselves a golden calf as their god. Cue God wiping out some of His people for, giving them a reason why no one should worship other gods other than Him.
Jack London's famous novel The Call of the Wild features a grizzled older sledding dog named Sol-Leks, with one blind eye. Buck, the mutt protagonist of the novel, takes a nasty bite when he approaches Sol-leks from his blind side and is careful never to do it again.
And for God's sake, do NOT harm John Thorton in front of Buck. Black Burton learned this the hard way, and so did the Indians when they killed him.
Do not call Yosyp Kazakov a Russian. He is not Russian, he is Ukrainian.
The Last Battle: The chapter "The Rashness of the King" refers to King Tirian going berserk and chopping off a few heads when he sees Calormenes chopping down dryads' trees and harnessing and whipping a Talking Horse. He blows his party's cover later when the Calormenes threaten a Talking Boar. Do not mess with King Tirian's subjects!
Taran, the hero of the Chronicles of Prydain, starts out as rash and foolhardy but undergoes some incredibly awesome Character Development over five books. You can still get him awfully mad, though, if you insult or threaten his beloved Princess Eilonwy (or have the misfortune to be a prince to whom she's expected to be betrothed).
Merely being around the fluffy bunnies of a particular cartoon universe turns the main villain of Craig Shaw Gardner's Cineverse Cycle into a ranting Gargamel expy.
For the love of all things holy and French, do NOT make fun of Cyrano de Bergerac's nose. You will be publicly outwitted, humiliated, and stabbed.
Derek isn't exactly the most easygoing person to begin with, but he's generally pretty reserved and doesn't lose his shit over most things — unless someone he cares about is in danger. This is only compounded by the fact that, as a werewolf, his instinct to protect his "pack" is taken Up to Eleven. If he sees you in the process of harming his father, his brother, or his girlfriend, nothing except for his death will save you. And considering that his girlfriend is a superpowered Necromancer who can raise the dead with a thought, possibly not even that.
The Dark Tower: Roland of Giliad has a few of these mostly concerning people to try to kill his Ka Tet/adopted family but being that Roland is an experienced and crafty warrior, he keeps his cool and does things like calmly insult then gun down 30 men in revenge, refusing any offer of surrender.
In Night Watch, Carcer — a rather psychopathic villain who would rather kill you for your watch rather than ask you the time — becomes inordinately angry when his rank of Sergeant is abbreviated to "Sarge."
Subverted in Hogfather, in which the villain Jonathan Teatime (who will usually kill people for no reason at all) gets very mildly annoyed when people mispronounce his name (it's pronounced "teh-ah-tim-eh"), at one point tiredly commenting "Please don't try to distract me."
Played straight with Medium Dave Lilywhite in the same book: "If he had a fault, it was a tendency to deal out terminal and definitive retribution to anyone who said anything about his brother."
The monk Marco Soto in Thief of Time has a very un-monk-like mass of long black hair. He is a calm, tranquil person... unless you try to touch it. The real life person the character is based on and named after is much the same way. Not that you'd want to touch his hair anyway. It eats combs, people. In the same book Pratchett actually refers to this trope, although by another name. As he puts it:
Everyone has their own private exemption clause. "But not on a Sunday," "Only if I feel like it" or in this case "Not the hair. Nobody touches the hair, okay?"
Don't sort people by importance in front of Sam Vimes, or threaten his family. In Thud! he gets scary when he is prevented from reading to his son at 6:00. "That! Is!! Not!!! My!!!! Cow!!!!!"
His wife, Lady Sybil, is a very sensitive and easygoing person — especially for someone of such high birth — until you threaten her family. After that she'll probably beat you with something very massive, or improvise something worse, and lecture you about you misbehaving. She doesn't like rudeness much either, though her standards there are interestingly complex, and she really, really despises anyone who is cruel to swamp dragons.
Death doesn't take kindly to anybody messing with his harvest, and he tends to do bad things to people who do bad things to cats. He also tends to go batshit at the Auditors of Reality if they attempt to manipulate humans into making life, well, less 'messy' as this to Death is breaking The Rules. Also, he's pretty bloody fond of life in general and the Auditors messing with it is a sure way of driving him as berserk as you can make a gland-less supernatural being.
Don't call Mort a boy.
Don't threaten the existence of Susan Sto Helit's grandfather (Death), or any of the children she looks after. Time and space don't exist for her (she's canonically Death's successor), she has a magic poker, and she will show you why it's best not to mess with her reality.
Tiffany Aching loves her sheep, her family, and her homeland. Don't mess with any of them.
Never mess with a wizard's hat. Even the normally harmless, cowardly Rincewind will go ballistic on you if you touch his hat.
However, one of the few times Rincewind is ever genuinely angry comes in Interesting Times, when the rebellion decides to play the Doomed Moral Victor card. To Rincewind, who lives by the rule that you only have one life and everything else is replaceable, this is utterly disgusting, and he lets them have it.
Lord Vetinari, the sober, serious, Magnificent Bastard Patrician of Ankh-Morpork kills people who hurt his dog, Wuffles. He also sentences mimes to death-by-scorpion, for crimes against humanity.
If you don't want to get the crap beaten out of you (and nailed to a wall if you're another troll) by Detritus, don't deal drugs.
Granny Weatherwax has a few buttons, some more minor than other. Treat her disrespectfully (for instance, expecting her to move out of the road when you are driving a cart) and she will get... angry. Threaten her friends (a rather loose and not exactly literal concept for Granny) and she will take you down. However, if you even threaten to take her mind from her, there are no words in any language to describe how utterly screwed you are.
Don't deliberately keep your clock excessively fast if Jeremy Clockson visits you a lot.
While just looking at a Feegle wrong can provoke him, one thing you should never do if you want to continue breathing is threaten to dig up a Feegle mound.
Also, dwarfs can be quite touchy about their beards and (especially) their heights. The degree of anger ensuing may vary with the dwarf and the book, but it's usually better not to risk it. Careless use of the right insults generally can usually send a dwarf pretty mad; one of the worst, in their own tongue, translates as "lawn ornament".
Don't insult or offend Aliera e'Kieron where her father has a chance of hearing about it. Adron will blow up cities to get revenge.
Do not mess with the minds of Vlad's people. He will not tolerate it, and will ignore his primal fear of Morganti to tell the owner of a Great Weapon so.
Dragonriders of Pern: Anne McCaffrey did it first, with dragonriders whose dragons have died most often becoming suicidal and/or insane. One of the Oldtimers deliberately arranged for his dying dragon to expire in a failed mating flight, specifically so he could go berserk himself and kill F'lar.
Dragon Slippers: Creel kills Larkin after the poor idiot lets it slip that she helped the evil princess find Shardas (and 'hurt' him). She goes even more off the wall when she finds out what Amalia did to her friend.
Velika is not pleased with anyone who threatens her husband or friends. she's the queen of the dragons. is it really worth it? no.
Dora Wilk states that every cop has a crime that's his/her own Berserk Button. For her it's domestic abuse, for Anita it's rape and Witkacy hates drunk drivers. Also, don't hurt any member of Dora's "extended family". Don't even try to.
If you hurt someone Harry Dresden of The Dresden Files cares about, he will burn a smoking hole in your body. And as we learn in the Wham EpisodeChanges, if that someone is his daughter he hadn't known existed, he will not only kill you, but your friends, your family, your entire race. He will completely sacrifice every principle and sell his soul just to obliterate you and everything like you from existence.
And if you ever threaten Harry, Ebenezar will drop a freaking satellite on you.
And if you dare harm or threaten a child on John Marcone's turf, you're going down. Even if that child is a Person of Mass Destruction who could vaporize him with a thought.
Angels in the Dresdenverse are generally extremely pleasant in demeanor and very much the Good Guys. There are two things that can piss them off. 1: Insisting that they make a choice. Angels cannot choose, at all, and are a little bit pissed about it. 2: Shortening their names. Names are power, and they are very powerful creatures. Dresden finds this out when he calls Uriel "Uri." Considering the two letters he chopped off mean "of God," you can understand why the angel was displeased.
Harm Justine, Harry or Inari, and you will have to face an extremely pissed off Thomas Raith, and you will find out why pissing off one of the most powerful vampires of the White Court is a really bad idea.
For Murphy, someone trying to bully her is one, harming Harry is another.
For Morgan, someone who breaks the Laws of Magic. Or hurts Luccio.
Do not hurt a child while Harry is around, especially not one under his protection. You'll be lucky if he just kills you. As it is, he might indulge in Cold-Blooded Torture that would make the Punisher blink.
In the 87th Precinct novel Ice, "man of the cloth" Brother Anthony does not take kindly to people who don't think his somewhat... er... ample girlfriend Emma is as sexy as he thinks she is. And don't think for a second that Emma doesn't return his affection. Tim, the novel's Big Bad and Brother Anthony's killer, found this out the hard way after he got off scot-free for his main crimes; she killed him in return.
In the Elenium trilogy by David Eddings, the Knights of the Church — specifically the Pandion order, but several members of the other orders as well — have a collective Berserk Button that gets pressed if anyone harms or threatens to harm Sephrenia, the beloved tutor in magic to generations of soldiers. Their Big Brother Instinct gets kicked Up to Eleven in the Tamuli trilogy, the Elenium's sequel, when The Dragon is revealed to have been messing with her for a long time.
Interestingly, this Berserk Button also applies to the renegade knight Martel, who was ejected from the Pandion Order for pursuing dark magical instruction and has since allied himself to an enemy faction. When one of the men with whom he is working says something nasty about Sephrenia, Martel picks him up by the throat and tells him to never insult her again or he will pay.
Feel free to harm protagonist Sparhawk's wife or daughter. Go ahead. Just remember when you do that Sparhawk has gods for allies, and he has no qualms about tearing continents apart in order to pay you back tenfold. Sparhawk himself is the guy who the gods are scared of, and he's on pretty close terms with the world's creator entity. So just don't piss him off.
Farworld: Riph Raph is *not* a lizard. He breathes fire.
Han Pritcher in the Foundation novels is initially a rebellious intelligence operative, resentful of being passed over for promotion and more than willing to break orders to do what he sees as right. Then he's controlled by the Mule. He's promoted all the way from Captain to Colonel and then to Lieutenant-General and becomes the Mule's best operative, but if his control were ever to be broken...
And in the prequel novels, don't lay a finger (or a blaster, or a neuronic whip) on Hari Seldon, unless you want Dors Venabili to cut you into tiny pieces.
Gotrek & Felix: An elf shouldn't ask Gotrek to shave his giant beard so he could walk past. Gotrek is something of a berserker, and if he calmly requests that you repeat yourself, find a really deep hole to hide in, fast!
Examined in The Sleeping Dragon, the first of Joel Rosenberg's stories about a group of college kids transported to a fantasy world. A dwarf warrior needs to go berserk to break the group out of a bad situation. He understands that he needs to find a point of anger and build on it. Cue flashbacks to life back on earth, where he was wheelchair bound with MS. Not enough, no matter how deep he goes. Finally in despair he finds the button "So here I am, just as helpless as I've been my entire life." Last words of the chapter: "He went berserk."
½ Prince. Do not ever try to hurt Prince, or Gui will get you.
And Gui, do not go Yaoi on Prince. Prince will get you.
Snape has a Berserk Button of sorts too. He does some pretty irrational things after being called a coward, like revealing himself as the Half-Blood Prince.
The word "coward" brings up more than just that freakout. When Harry calls Lupin a coward while the latter is having a panic attack because his son might be a werewolf, he gets angry at Harry and actually attacks him before storming out.
By all means, do NOT try to hurt Lily Evans in any way unless you want Snape to bring his wrath down upon you. Voldemort could testify to this, if he wasn't Stupid Evil and didn't resolutely deny it.
Lily herself hates being called a mudblood (the magical equivalent of a n-r). She resolutely defends Snape, her childhood friend, against bullies even after he joins the Death Eaters- but Snape calling her that insult is what finally pushes her to abandon him.
Never insult Dumbledore within earshot of Hagrid. That will show you what a Bad Idea is to piss off a Gentle Giant. He will magic transforming yo ass.
It's also a bad idea to hurt Harry or any of Hagrid's furry friends. When his dog Fang gets hit with a spell, he hurls the perpetrator ten feet through the air!
When, in the Battle of Hogwarts, he meets the now-Death Eater Macnair who tried to kill Hagrid's Hippogriff, Buckbeak. He is promptly hurled face-first across the Hall and into a wall.
Dumbledore has his own button: he's perfectly calm and cool while he is told he's lost his marbles, or while Harry throws a tantrum, implicates him in the death of Sirius, and wrecks his office... but threaten to harm his students, especially if said student happens to be HARRY (as the Dementors learned the hard way when they sabotaged the Gryffindor vs. Hufflepuff match in the third book), and God have mercy on your soul. If you even have a soul to begin with, which the Dementors don't.
The Dementors themselves are also a Berserk Button for Dumbledore. He did not approve of the Ministry recruiting these soul sucking monsters as prison guards.
Dobby is also very protective of Harry Potter ever since he was freed, conveniently appearing more than once and quoting his trademark "You shall not harm Harry Potter!" Dobby is so devoted that he even risked (and lost) his life in order for Harry and the others to escape Malfoy manor.
"Kreacher will not insult Harry Potter in front of Dobby! No he won't! Or Dobby will shut Kreacher's mouth for him!"
For that matter, Ron doesn't typically get more aggressive than the Belligerent Sexual Tension-style bickering with Hermione... but should anyone else go after Hermione, all bets are off. In Chamber of Secrets, he twice has to be physically stopped from laying the hurt on Draco Malfoy.
"Let me at him," Ron growled, as Harry and Dean hung onto his arms. "I don't care, I don't need my wand, I'm going to kill him with my bare hands!"
Ron's also very protective of his little sister, Ginny. In "Chamber of Secrets" he has to be stopped from trying to curse Malfoy for being mean to her and in "Deathly Hallows" he even gives Harry a rather rough talking-to when he thinks Harry might be toying with her.
Professor McGonagall really hates it when people play dirty, particularly in Quidditch matches. On several occasions she's shown to forget herself in rage when she witnesses foul behavior (the most notable incident happening in the third book, when several Slytherin players attempted to sabotage a Gryffindor/Ravenclaw match by dressing up as Dementors to scare Harry, who justifiably sics his Patronus on them for the effort— and she didn't think the Patronus alone to be punishment enough for the offending parties).
Although it should be said that Harry himself often identifies Fred and George Weasley cheating out of spite against the Slytherins, and we never hear her chew them out in the same way. It may come down to House Loyalty in this situation.
This generally doesn't happen until after the Slytherins cheat first, though, so Harry and the audience tend to think of it as 'payback' or 'evening the field'. It's possible McGonagall agrees.
NevilleLongbottom flips out after Draco says they should send Harry to St. Mungo's as they have special floor for people with brain damage. Considering what happened to his parents, it's not much of a surprise. Harry and Ron desperately grab hold of Neville, who is trying so hard to break loose and murder Malfoy that Snape thinks the 3 of them are fighting." Any mention of Neville's parents in a negative light will result in a beatdown that even the most hardened Death Eater doesn't see coming.
Do NOT attack people from behind in front of Mad-Eye Moody (even if it's just someone impersonating him).
If one values his/her own life and dignity, Don't! Ever! Call the Centaurs half-breeds in front of them, or else they will go extremely berserk on them.
On that matter, don't even accidentally imply that you used them, as that is not going to be different for them.
Voldemort's a psychopath anyway but don't call him Tom! Or threaten his horcruxes! Come to think of it, don't go near the guy.
Don't insult Minerva McGonagall in front of Harry Potter. And really don't spit at her. Out of everything he has seen and all the horrors he has endured, it is this that prompts Harry to fire a Cruciatus Curse at Amycus Carrow. Remember the only other time he did that was to Bellatrix Lestrange, who had just killed one of Harry's two critical father-figures - and then it was less effective.
Don't call him a liar and say he made up Voldemort's return either.
And do not, under ANY circumstances, insult his parents.
Hermione has her own button: she will SCAR YOU FOR LIFE if you dare betray Dumbledore's Army to Umbridge. Just ask Cho Chang's friend, who was stupid enough to betray the group and was cursed by Hermione in such a fashion as a direct result.
In "Hidden Talents" by David Lubar, the narrator gets sent to an end-of-the-line alternative school because he has a chronic habit of pressing other people's Berserk Buttons. Teachers, parents, classmates — if you get in his face, he always finds that one nerve to hit. Turns out he has a psychic ability to sense other people's sources of pride and anxiety.
Harm anyone Honor Harrington considers to be under her protection, and nothing will save you.
Harm Honor herself (or even think about it), and Nimitz will rip your face off. Likewise, harm either member of a human-treecat bond and you will die. Even if you're a hexapuma and the human in question is an eleven-year-old girl with a broken arm.
Jamie Candless was surprised to learn that he had a berserk button. It took Honor being captured and separated from him to bring it out, after which he became incredibly calm.
Even beyond Andrew's feelings about his Steadholder, all Grayson men have this Berserk Button where women are concerned. So when the Grayson Space Navy adopts Honor, and is then informed she has been executed by StateSec... Well, a particular Havenite task force learned how monumentally screwed they were when a Grayson admiral's order, in clear, over the tac channel was "The order is, Lady Harrington, and no mercy!" (Echoes of Honor) This terrifies the Manticoran members of the team, until they realize the order was "No Mercy" (which is legal), and not "No Quarter" (which isn't).
Harm Honor Harrington's love Paul Tankersley, and Honor will come after you. And then after the man who hired you. And, no, a personal request from the Queen would not be enough to stop her, not that Elizabeth would ever ask.
So your stupid power play killed Reverend Hanks, Adam Gerrick and a school full of children, and Honor nearly died as well? Her only question for the Protector is "Do you wish this man crippled, or dead?"
Honor's button gets pounded in Mission of Honor. Its implied she's going to be in Tranquil Fury for the next several books.
"It was a merciless something, her "monster" — something that went far beyond military talent, or skills, or even courage. Those things, he knew without conceit, he, too, possessed in plenty. But not that deeply personal something at the core of her, as unstoppable as Juggernaut, merciless and colder than space itself, that no sane human being would ever willingly rouse. In that instant her husband knew, with an icy shiver which somehow, perversely, only made him love her even more deeply, that as he gazed into those agate-hard eyes, he looked into the gates of Hell itself. And whatever anyone else might think, he knew now that there was no fire in Hell. There was only the handmaiden of death, and ice, and purpose, and a determination which would not — could not — relent or rest."
Manticore hates slavery. A lot. Also, piracy will get you shot and your miserable corpse Thrown Out the Airlock.
Queen Elizabeth is "a little irrational" where Haven is concerned. Like the sun is a little warm. Didn't help that they killed her father, for a start. The people of San Martin share this sentiment.
Barely averted in Ashes of Victory. Baron High Ridge made the mistake of invoking the memory of her recently assassinated uncle to justify making peace with the same Havenites who had carried out that assassination. Elizabeth threatened to smash his face into the table.
The first official act of the Kingdom of Torch was to declare war against the planet Mesa, home to the slave-trading Manpower Incorporated. This should tell you a little about how they feel about Manpower and slavery.
Don't be an incompetent, selfish, power-hungry aristocrat who shirks his responsibilities, and if you do, have the good sense not to show those traits to Michael Oversteegen. He will inform you that you have the brains of a carrot, and then he'll really get going.
So you've been scheming for centuries to use the Star Kingdom of Manticore and the Republic of Haven to annihilate each other before you finish them off, killing millions of their own people in the process? Please don't let President Eloise Pritchart and Queen Elizabeth III find out about it. Because if you do, they will ally themselves and their star nations together, take the combined results of a twenty-year-long Lensman Arms Race, put the very best military brains in three star kingdoms (Manticore, Grayson, and Haven) in command of all of it, point it in your direction, and let go — with prejudice. Nice Job Fixing It, Villain!
So you take Honor Harrington prisoner. Fair enough, that's howwar goes. So you're State Sec, you take Honor prisoner, you abuse her, you hurt her treecat, you nearly starve her to death, and then you fake her execution and dump her on a prison planet, and then you send assassination orders for Javier Giscard and Lester Tourville? And you let the best hacker and tac witch in the entire galaxy know about it? Bad plan. Because that little tac witch will, with a tiny, innocent data packet and a few keystrokes, annihilate two whole squadrons of State Sec spaceships by ensuring their fusion bottles fail, causing them to vaporize at the heart of a newborn star. And all she will have to say about it is "Oops."Don't anger Shannon Foraker.
Don't tell Dame Estelle Matsuko that she ought to stop enforcing local trade laws because it's upsetting the heads of the trading cartels. This goes double when Dame Estelle's people have just been very badly hurt in a raid on a suspected drug lab. There's a reason Honor Harrington described her as "elementally enraged".
The title character of "Hop Frog" by Edgar Allan Poe is a short, misshapen jester who meekly puts up with the abuse heaped on him by the king and noblemen he serves... until the king throws his drink in the face of the dancer Trippetta, the only person who was ever nice to him. He immediately devises a scheme that ends with his tormentors getting burned alive in full view of a crowd.
In the Immortals Quartet by Tamora Pierce, do not, under any circumstances, screw with Daine or her friends. When she thought Numair had been executed, she went on a Roaring Rampage of Revenge with UNDEAD DINOSAURS. And the cute little woodland critters? Yeah, don't screw with them either. Daine likes little woodland creatures, and does not care for animal abusers. At all.
Also, Numair will turn you into a tree if you even try to hurt his student. So don't.
Dragons dislike it when you cause the death of their young.
In the In Death series, harm Eve and after the NYPSD makes your life a living hell, Roarke will show you new types of pain. The same applies for harming Roarke where Eve is concerned.
Led to a Crowning Moment Of Awesome for Roarke. A Smug Snake hacker managed to program music that caused Roarke to more or less rape Eve. Roarke then asks for five minutes alone with him, at home, before Eve interrogates him officially. When she accepts, he locks all the doors and cuts off surveillance. He comes out without a mark on him, but when Eve does an official interview a day later, the mere mention of Roarke causes the man to break into a cold sweat.
Like most examples of this Trope, if you hurt, injure or kill another cop, no matter who you are, the NYPSD will drop everything to hunt you down.
No matter how injured she is, even when a case is over Eve will still fight to avoid going to a hospital.
Go on, I dare you to accidentally infect Barrin's daughter Hanna with lethal Phyrexian plague. In Invasion, when she dies, Barrin gets so pissed off he goes on a suicidal Roaring Rampage of Revenge that nearly destroys two planes of existence.
In the Jeeves and Wooster story "The Love That Purifies" Aunt Dahlia has a bet with a friend that her son Bonzo can behave better than her friend's offspring Thomas while a mutual acquaintance is staying with Bertie; Bonzo is toeing the line so he can be worthy of movie star Lillian Gish, who he has a big crush on. But Thomas is behaving even better and all looks lost - until Jeeves suggests to Bonzo that he speak ill of Thomas's beloved Clara Bow...
The Last Dragon Chronicles: Harming animals or Lucy's beloved clay dragons will set her off like crazy. Suggesting, at any point in the series, that David is actually dead will earn you a one-way trip to the ER. Her crush on Tam can also make her explode if someone (Zanna) patronizes her on the topic. Also, Zanna herself isn't one of Lucy's favorite people in The Fire Eternal.
In the David Gemmell book Legend, Rek's quality as The Berserker first comes out when someone tries to reach into his mind and he loses it in spectacular fashion.
In his few appearances in the Dark Elf books by R.A. Salvatore (the ones about Drizzt Do'urden, for those who don't already know), a neat freak Dwarven sage by the name of Fredregar "Fret" Quilldipper has a rather interesting berserk button. Get his immaculately clean clothes dirty at all, or even threaten to, and he will threaten your life at best (to the point in one instance of backing down a battlerager by the name of Thibbledorf Pwent), or will go completely nuts and use his little hammer to beat the target of his rage into a bloody pulp. (This, by the way, will often result in blood and gore getting on his clothes, which causes him to go into an even stronger killing frenzy against the target or targets of his anger.)
Miss Trunchbull hates many things, but one thing she apparently really can't stand is pigtails.
Matilda's being accused of something she didn't do - and this is actually what triggers her Psychic Powers in the first place.
The title character of the Mediochre Q Seth Series is a dracologist. As such, dragon-slayers are about the only people he's willing to murder.
Mercy Thompson is a Berserk Button for several people, from the Alpha of the local werewolf pack, to the powerful fae she used to work for. But the most fearsome one is the Marrok, ruler of the North America werewolves. As described by his son:
Samuel: My dad raised Mercy in his pack, and he couldn't love her more if she were his own daughter. For Mercy, he would declare open war on the fae, and damned be the consequences.
Harm Jesse Hauptmann, and her werewolf dad will rip you to shreds. If you take him out of the picture, Mercy will not rest until she has hunted you down.
In The Name of the Wind Professor Lorren is an almost completely stoic man, so much so that Professor Exl Dahl has a running bet that no one will ever get him to smile. However, God forbid you ever, EVER threaten his books in any way, shape, or form. Kvothe got off lightly.
In The Wise Man's Fear Kvothe's own is revealed to be impersonating Edemah Ruh, then actually doing the things people accuse them of doing. He responds by killing them all but the leader, who he leaves to die slowly of a gut wound.
And Bast's is people hurting or humiliating Kvothe.
In Needful Things, don't call Danforth Keeton "Buster." He just might kill you. And not "just might," as his wife discovered when she did it.
One minor character from Simon R. Green's Nightside series, who fed on the intense emotions of others, went around in public dressed as a Nazi SS officer while wearing a large Star of David, specifically in hopes of pushing other people's Berserk Buttons.
Touchstone goes into a berserker mode once, running up a hill carrying an injured Sabriel away from danger. It's mentioned in the next book that once when an assassin tried to stab Sabriel with a serving fork, he threw the 6 foot assassin across the table before trying to pick up a solid marble throne and crush him with it.
Sam has a half-berserker moment in Lirael when he and Lirael take on Chlorr and her Dead Hands who are ambushing the group of innocent people. He almost gets killed, but he does try to be as nuts as his dad.
In the 3rd Origami Yoda book, The Secret of the Fortune Wookiee, Tommy wipes his nose on an origami snow trooper made by his enemy, Harvey. Harvey had a Berserk Button when he saw this... during an assembly!
William Maldonado's Outsourced has the main character, Isaac Fisher responding poorly to assertions that his wishes are just a phase.
In the Paladin of Shadows book Unto the Breach, seeing Gretchen's body causes Kacey to lose it and pull the gunship with fourGatling Guns into use. The Chechens responsible pay in rivers of blood.
"You can trick Travis McGee. Maybe beat on him. If you're lucky he might shrug it off. But whatever you do, don't kill his friends." Cover blurb for Pale Gray for Guilt.
In The Pale King, Toni Ware really loves her dogs. Do not mess with them if you value your life.
The Phantom of the Opera: The Phantom has a Berserk Button a mile wide. Although in some adaptations it is more a bad sunburn wide. But anyway, NEVER take his mask off, or even try.
Actually, a worse thing to do would be to insult or harm his protege.
Actually, Erik goes around for most of the book without his mask on, even sitting down to dinner with everyone at the managers' party in the first chapter sans mask. From the stories told by Buquet and the others, it seems that everyone has seen him without his mask, because Erik wears it so infrequently. The reason Erik loses it when his mask is removed is because Christine is the one to do it. He thought he had a shot at winning her affections, but once she sees his face, Erik despairs.
Do not criticize Sgt. Escrima's cooking unless you're a masochist or enjoy hospital stays.
In The Pilo Family Circus, physically harming Goshy the clown — even shoving him — will result in his meek and mild brother Doopy flying into a homicidal rage and thrashing the offender to a pulp with a scream of "HEY HEY HEY HEEEEEEEEEEEEEY!"
Do not, ever, try to bring harm to Nimashet Despreaux, ever. If you do attempt it, you will not only incur the wrath of Prince Roger Ramius Sergei Alexander Chiang MacClintock, but also his bondsman, said bondsman's wife, and a whole army of pissed off Human Marines and Mardukans. The line starts with Roger, and his Dogzard, which ensures there will be nothing left to bury. Just ask the poor idiots who tried to force Roger to give up his girls in order to make a meal out of her.
Refrain from harming Empress Alexandra as well. Thomas Catrone will not forgive you that.
Catrone: I've had some time to get over it. Marinau brought me the word. All of it. He brought it in person, along with a couple of the other guys. Roger: They have to hold you down? Catrone: I nearly broke his arm. It catches me, sometimes. I've been wracking my brain over what to do, other than getting myself killed. I don't have a problem with that, but it wouldn't have helped Alex one bit. Which is why I didn't hesitate, except long enough for some tradecraft, when you turned up. I want those bastards, Your Highness. I want them so bad I can taste it. I've never wanted to kill anyone like I want to kill New Madrid. I want a new meaning of pain for him.
In the original novel of The Princess Bride, Prince Humperdinck is incredibly calm, cool, and collected. It's what makes him such an amazing hunter. But when Buttercup calls him a coward and tells him that there's nothing he can do to break the bond of love she shares with Westley, he flips his shit, locks her in her room, and then rushes down to the Zoo of Death to kill Westley. This happens in the film version too, but he comes across as far more berserk in the narrative.
Eugene, from Purple Hibiscus, does not like it when you question Christianity.
In Puss-Cat Mew, you don't EVER diss the title character in Joe's hearing. He will turn you and your companions against each other and then kill you.
Salamandastron; don't threaten Urthstripe's foster daughter, poison or just flat out kill his hares...he will go through your army with a forge hammer if he has to. Then don't kill him because then his brother will mess you up even more.
Mattimeo; you stole Orlando the Axe's daughter...he'll use that Axe to cut through stone to kill you.
Long Patrol/Marlfox; there's a reason she's called Cregga "Rose Eyes."
Pearls of Lutra; the Abbot and Viola are captured...Martin, a mouse, goes BERSERK and it takes a BADGER to restrain him from leaping off the top of the Redwall battlements so he can get at those who did it.
Outcast of Redwall; Sunflash's Heterosexual Life Partner Skarlath is killed with a poison arrow by the fox Nightshade the scene cuts away right before Sunflash kills her (Sunflash wields a MACE so go ahead and imagine it).
In fact, just stay away from badgers. And don't touch the children of other woodlanders either; if their parents don't fuck your shit up, the kids themselves will.
The eponymous Reynard from The Reynard Cycle clearly has one. In Reynard the Fox he shockingly beats a beggar woman to death because she reminds him of his mother. In Defender of the Crown, he nearly strangles a priestess to death when she continues to insist that Queen Persephone is dead.
In Riesel Tales: Two Hunters, Runge Margavo doesn't usually get into too much of a knot about things, even when his business partner Ramy Dusotes pesters him about a question he doesn't want to answer...unless it's a flaw he really wants to keep hidden from her. Cue a verbal blow-up.
In Rogue Sorcerer, Aiden completely loses it and almost gets himself killed when he sees his sister bleeding on the floor of Lyr's inn.
In Romance of the Three Kingdoms, the act of killing Guan Yu and Zhang Fei by the Wu kingdom drove their elder brother Liu Bei into full blown fury mode. Usually a man of virtue and honor, Liu Bei's thirst for vengeance truly knew no bounds during his campaign against Wu with things like executing his own adopted son Liu Feng, ignoring the advice of his close friends and advisors Zhuge Liang and Zhao Yun, threatening to boil Sun Quan (ruler of Wu)'s heart and eat it, etc.
Septimus Heap: Don't try to kill Septimus or else Jenna will take you down.
Sherlock Holmes, as much as he prides himself on his rationality, does NOT like seeing Dr. Watson in danger or pain. In "The Adventure of the Three Garridebs," when Watson gets shot in the thigh by Evans (don't worry, it's Only a Flesh Wound), Holmes pistol-whips Evans in retaliation and sends him sprawling. Watson even mentions Evans' face being bloody, in a story that's pretty sparse on description/detail. Holmes then informs Evans that he's very lucky, because if he had killed Watson, he would "not have got out of this room alive."
It isn't just Watson either. In the story "A Case of Identity", after revealing how a man screwed with his stepdaughter's heartstrings in order to keep hold of her family fortune, Holmes can't legally have him arrested but thinks what the stepfather has done is so despicable that he grabs a riding crop and chases him out of the flat, fully intending to give the guy a thrashing himself.
As a general rule, Holmes really hates it when a person who has hired him for help is utterly wronged, or worse, either injured or killed. When Abe Slaney from "The Adventure of the Dancing Men" killed Holmes's client HiltonCubbitt and this drove his wife Elsie (who was Slaney's ex-girlfriend) to attempt suicide, Holmes gave him a brutal"The Reason You Suck" Speech telling him how much he had ruined poor Elsie's life with all of his harrassment before getting him arrested.
Sisterhood Series by Fern Michaels: The Jury shows that if you mistreat a horse, Nikki Quinn (who loves horses) will come after you. Final Justice reveals that Lizzie Fox really does not like being called a coward. Fast Track shows that the president of the World Bank Maxwell Zenowicz prefers that you call him Maxwell or Mr. President, and if you don't or if you call him Max or Maxie, then you will taste his wrath. Deja Vu reveals that Henry "Hank" Jellicoe did not react well to being called a monster.
Barbara, the hero of the Special Circumstances series, is rather nice and accepting of others' religious beliefs. If someone speaks badly of Christianity, however, all bets are off.
Spenser is a dogged pursuer and he has a very large group of tough guys around him on both sides of the law who typically follow a strict code of honor. If you go after Susan Silverman, though, you will have everyone from homicide detectives to mafia hitmen backing up Spenser and Hawk as they hunt you down and kill you dead.
Stu does not take kindly to doctors who don't do full disclosure and keep him locked up.
He also does not take kindly to Frannie getting hurt. Moreso if half the Free Zone gets hurt with her. His reaction to finding out it was Harold and Nadine, the cold, vengeful smile and the Fist of Rage scared Franny badly and she told him never to do it again.
Randall Flagg does not take kindly to drug use. Just don't go there unless crucifixion appeals to you.
Harold doesn't take kindly to Stu's advances on Franny. They weren't actually a couple, but Harold believed they were in his mind and saw Stu as stealing her and lying. That rage, fed by Flagg's encouragement,led ultimately to the bomb he set off with Nadine. But even in the beginning, he thought Stu was a troublemaker who was going to rape Franny and didn't even want him along for the ride.
More literal than most: in Wicked Appetite, by Janet Evanovich, Hatchet becomes very violent at any disparaging remarks about his sanity (or lack thereof).
Family and friends seem to be a Berserk Button for the Skywalkers in general.
Also, if you mess with Tenel Ka's friends, she'll mess up you!
Likewise, Tenel Ka's rival Tamith Kai freaks whenever someone brings up how Tenel Ka busted up her knee-cap without breaking a sweat. Tenel Ka makes it a point to ask "How's the knee?" every time they cross paths.
In the Wraith Squadron books, Tyria Sarkin, the worst pilot in a squadron of Last Second Chances, responds to a teasing offer from a squadmate that he hack into the database and raise her scores by lunging over the table, bringing him to the ground, and repeatedly punching him in the face. Her Reasonable Authority Figure, while putting her on report, tries to get her to explain herself, but she doesn't. He'd thought she was the steadiest of the new recruits. Later she confesses to being the victim of a scam during training - she'd struggled with her scores, her best instructor wanted to have her get him an X-Wing to sell on the black market, and when she refused he revealed that he'd been boosting her scores all along, and if she turned him in he'd turn her in. So she did nothing and graduated at the bottom of her class.
This is fairly obvious, but don't mock Chewbacca's death around Han. He started a fight with a group of Trandoshans when Bossk did so, and they came out worse.
In the Temeraire universe, the marriage-like bond between dragon and handler means that dragons will, generally, flip their multi-tonne shit if their captains are hurt, and vice-versa. Captain Laurence, though, deserves special mention: raised the third son of a Lord, he becomes an aviator only after a long career in the Navy, with manners and a sense of social mores and politesse that most aviators just don't bother with. He's truly a gentleman's gentleman. However, if someone insults Temeraire or mistreats a dragon in any way, he will not be responsible for his very violent actions.
He doesn't take too well to people insulting the Aerial Corps, either. But then, none of the aviators do.
Apollos is perfectly willing to die — he refuses to kill an innocent man. But mention that the girl he loves was murdered by said innocent man, and you have a monster (who wants to kill anyone connected to her death — including you). Now would be the time to run.
Also applies to Gid. Touch his friends and die.
John Collier's short story "The Touch of Nutmeg Makes It" features a man acquitted of killing another man for no apparent reason. Some time later he is relaxing with a friend, musing on all that happened; in the course of things the friend offers to make him a cocktail. The man begins to give him instructions on making a specific type of drink, in particular giving a dash of nutmeg. He is very particular about the nutmeg, because a man that would dare to leave out the nutmeg, the man that would dare do such a vile thing...
Trapped on Draconica: Zarracka can't stand the song 'goblin queen' because she had to play the role of 'goblin queen' whenever she played with her sister, Daniar. Singing it in her earshot drives an already sadistic girl to homicidal fury.
In Ruth Frances Long's The Treachery of Beautiful Things, after years of being told that her brother's disappearance couldn't have happened as she said, when Jack uses illusion to persuade her that she just had another "incident", but the advent of the Fairy Queen breaks it, her rage nearly sends her at him. Only the sudden realization that she is in grave danger from the queen manages to quell it.
The (not really) Big Bad Wolf, as portrayed in The True Story of the Three Little Pigs, is really a nice fellow who was just trying to borrow a cup of sugar to use for a birthday cake he was baking for his grandmother. When the pig in the brick house insults the wolf's grandmother, the wolf gets mad and starts trying to break in.
If you ever find yourself in the world of Warrior Cats, do not attempt to touch Jayfeather's stick. He will murder you. Also, do not call any Clan cat a kittypet. And do not harm Sasha's kits. And if you don't want to face Squirrelflight's wrath, PLEASE do not pick on Leafpool.
Lanfear of the The Wheel of Time does not take kindly to being addressed by her real name. It's Mierin Eronaile, by the way.
That's nothing compared to her meltdown if you insinuate that Lews Therin/Rand doesn't love her or slept with another woman.
Keeping with the theme of the Forsaken, don't tell Moridin that he's irrelevant. He's also liable to throw offers of redemption square in the face of the person making them.
Also, don't treat women badly in front of the good guys. Or, in the later books, don't cross Rand al'Thor at all.
And do *not* mess with the main squeeze of the guy that's buddies with friggin' wolves and carries either a big-ass axe or a big-ass hammer.
Due to hideous mistreatment on his part, the title character of White Fang goes insane when laughed at for much of the book.
For Elphaba in Wicked, Animals, animals, even insects are a bit of an obsession. She has a major freakout when Killjoy goes after Chistery, as well as when the children at Kiamo Ko are bothering him.
In the world of A Brother's Price, it's usually safest to avoid even an appearance of posing any threat to any male's personal safety or his chastity. His mothers, sisters, and/or wives have no qualms about doing whatever they think they need to to protect their men/boys, and aunts and female cousins will happily join in if given the chance. This especially applies to the new husband of the princesses, who actually argue among themselves over who gets to do what to help him. It's also not a good move to pose serious problems to sisters-in-law of the Whistler family, who have a "mess with one of us, you mess with all of us" rule and are very effective in combat. Kij and her family find out all of this the hard way by kidnapping Jerin and threatening to force him into marriage to them. Since Jerin was born into the Whistler family, the Porters qualify as Too Dumb to Live by not only messing with the Prince Consort but running afoul of his highly militarily skilled birth family, who are also very loyal to their new sisters-in-law, the princesses.
Being rude to Hannibal Lecter or any one of the people he actually respects (namely Clarice), or heaven forbid bringing up his sister, is a very, very bad idea.
In World War Z, never hurt a dog in front of Darnell Hackworth. It doesn't matter if he's suffering from a fever, the rickets, and dangerously underweight, he will tear you a new one. Hackworth comments on it, saying that he hated dogs until he was forced to listen to puppies starve to death in a nearby pet shop.