- This is the entire premise behind John Grisham's A Time To Kill. After a brutal first chapter detailing the rape of his 10-year-old daughter by a couple of rednecks, Carl Lee Hailey (played by none other than Samuel L. Jackson in The Movie of the Book) goes berserk on the two and opens fire on them with an assault rifle (even though they were already on trial), catching a court deputy in the process. The deputy forgives him, as does the jury when they acquit him of murder charges by reason of "temporary insanity."
- Woe betide whoever dares to abduct Popsy's grandson.
- Conan the Barbarian: Although being mostly an Anti-Hero he won't hesitate to shed blood to save his family from any danger.
- The Jungle Book: Akela, who acts as a father for Mowgli despite not necessarily his adoptive father. And is a literal wolf. Baloo and Bagheera, too (despite being a bear and a black panther, respectively). Akela stood up for him when he was brought to the pack as an infant (after Raksha saved him from Shere Khan), Bagheera bought his life and protected him ever since, and Baloo taught him the ways of the Jungle - and when he's kidnapped by the monkeys, they join with Kaa to make it a day and a night the poo-flinging rabble will not live to regret...
- Mists of Everness by John C. Wright: Peter Waylock. Don't harm his son. Don't harm his son and pretend innocence. And don't beg for mercy, because Peter Waylock is a Person of Mass Destruction and you won't get any.
- The father in Cormac McCarthy's The Road is exclusively defined as his role as this.
- Sam Vimes in Thud!. THAT! IS!! NOT!!! MY!!!! COW!!!!!
- Sergeant Jackrum from the earlier book Monstrous Regiment is an example, being A Father to His Men who regularly kills, injures, or otherwise incapacitates anyone stupid enough to threaten one of his Little Lads. Until we find out that "he" is actually a she who's been masquerading as a male soldier for longer than she can remember, technically making Jackrum a Mama Bear.
- Subverted in Wyrd Sisters, in which the late King Verence tries to charge ferociously to the rescue of his son, but is balked because he's now a ghost and can't leave the castle.
- An Older Than Radio example comes from Hector Malot's Sans Famille. The travelling musician Vitalis practically purchased lead character Remi Barberin as his apprentice, but he genuinely cared for the boy and became his mentor and example. His "Papa Wolf" side shows more strongly when he discovers that the old man whom he was going to ask to look out for Remi in the winter actually abuses his protegees and forces them to steal for him, and later when he protects Remi from dying in a snowstorm... in a Heroic Sacrifice. And he was also hinted to be one in his first apparition, when he "buys" Remi... after witnessing how horribly his abusive stepfather Jerome treats him, therefore choosing to "purchase" Remi half to have an apprentice and half to protect him.
- Individual names are not given but in Harry Turtledove's Worldwar Tetralogy, the Alien Fleetlord is amazed at reports of suicidal Tosevite (read: Human) attacks by both genders on his forces. Its stated that the few humans that actually survive indicate their actions are because of harm done to a Mate or Hatchling by his forces
- Amelia Peabody: Dr. Radcliffe Emerson, Egyptologist-detective husband of Amelia Peabody, who is always short-tempered and becomes absolutely volcanic at any threat to his family. Since he is regularly described by his narrator-wife as "Herculean" in build, the results are impressive. For that matter, his son Ramses inherits this trait. Guess what? Their wives are definite Mama Bears; it's a close-knit family.
- Honor Harrington: Anton. Zilwicki. Messing with his kids is the last mistake entire secret societies ever make. The entire planet Mesa and its Ancient Conspiracy may yet fall through the chain of events set off the first time they tangled with him.
- Not to mention that we have yet to see his reaction to the latest atempt by Mesa to kill one of his daughters. The foreshadowing in At All Cost might give some clues.
- And don't forget Anton's best buddy Victor Cachat and Victor's mentor Kevin Usher, who got off their asses and did something about the corrupt Havenite ambassador, because of Zilwicki's daughter kidnapping. Honor herself has her moments -- the surest way to get her to kill you, is to mess with somebody in her care. In fact the whole series is full of Papa Wolf and Mama Bear moments, from the lowly Aubrey Wanderman to the Queen herself, to the whole nation of Grayson which are all, 2 billion of them, a bunch of Papa Wolves.
- Also don't forget Nimitz. He may be a Ridiculously Cute Critter most of the time, charming people's socks off to glom some more celery, but if anyone harboring murderous intent gets within spitting distance of Honor, he'll instantly transform into a six-legged, self-propelled chainsaw with absolutely no mercy. (He's also probably older than Honor's father, so he qualifies under the "Papa" portion of the trope as well.)
- And treecats as a whole can be this when one of their own is threatened. Bear in mind that one Not So Harmless treecat outnumbers six gunmen; when a hexapuma, an apex predator from the treecats' homeworld, corners one 'cat and the human he'd adopted, his clan's answer to his distress call is a Zerg Rush which turns that predator into hamburger. In Mission of Honor, the Mesan Alignment kills an entire treecat clan via a Colony Drop. The other treecat clans are strongly hinting they want in on the counterattack.
- And all Sphinxians are in turn Mama Bears and Papa Wolves to Treecats in general.
- In Perry Moore's Hero, Hal Creed, a 100% normal (granted of the badass variety) Human, beats the shit out of a Superman expy for threatening his son.
- Burrich in both the Farseer and Tawny Man trilogies. Just how awesome can a grumpy old man be? Trek across a glacier and kill a deranged stone dragon for the adopted son who let you think he was dead for 15 years, that's how awesome.
- Raptor Red's consort pulls a Papa Wolf to save one of Raptor Red's nieces from an acrocanthosaur. He has mixed feelings about doing so: he gets several cracked ribs, the chick isn't related to him, and Raptor Red didn't even see his heroic actions. It does, at least, mend his relations with Raptor Red's sister for a time.
- Most David Eddings characters fall into this at some point: if you go after their wives, kids, fiancees, or friends, they begin throwing around phrases like "boiling oil," "wring him out until his hair bleeds," and "kill him just a little bit." Then they catch you. Then you discover this was them being nice.
- This trope applies especially to Belgarath. He not only has a few Wolf-themed nicknames, but also likes to turn into a wolf whenever he has the chance, and is even married to one. It works especially well because most of the time he prefers to give off the impression of a lazy drunken hobo. Barak on the other hand is scary enough in his normal form, but whenever Garion's life is threatened, he goes into a berserker rage and turns into a bear.
- Belgarath certainly qualifies, particularly given the following exchange after Chamdar/Asharak the Murgo has killed - by burning them alive inside a stone house - Geran and Ildera, the parents of Garion and both of whom were much loved by both Belgarath and his daughter Polgara. Who are also two, it must be said, of the most powerful beings currently walking the earth:
Khonar (about Asharak): Our agent reported that he seemed a little nervous about something.
- When his turncoat brother kills Durnik, the 'son in law' figure, Belgarath Takes A Level In Badass and commits Zedar to the earth; literally. When he returns from the surface to the point that the book describes him as NOT what he was throughout the entire Belgariad, but "Belgarath the Sorcerer in all his fury."
- Polgara says herself that Asharak likely crawled under a rock someplace deep and dark and very well-hidden to hide, solely to escape from the wrath of her vengeful father. A man who, it must be said, is considered by Asharak and his people to be the equivalent of the Devil. Skilled Angarak sorcerers are terrified of being within fifty miles of facing him, and she has also admitted that his power is one of the only things in the world that has held the Angaraks back from just overrunning the west with sheer numbers. Not the sort of Papa Wolf you want chasing after you with a single-minded purpose so strong that he can literally ignore rest, food, and the other necessities of "mere mortals" for weeks or even months at a time.
- As Polgara once put it: He has his faults, but once he gets down to business, he's as inexorable as the tides.
- This applies to Garionas well, but only in the sequel to The Belgariad, The Mallorean, in which the entire plot revolves around Garion turning the world over to get his son back from an evil sorceress, leading to a very satisfactory pay off when he finally catches up with her
- Eddings seems quite fond of these graphic descriptions. As pointed out by Xanetia in the Tamuli, after Zalasta, former advisor and supposed ally, reveals that he has been working for the Big Bad Cyrgon since before the start of the series itself. And he has been deceiving and betraying Sephrenia, Team Mom and beloved by all the characters, for that same length of time, all in the hopes of killing the goddess she worships -- also Sephrenia's younger sister via reincarnation - and possessing her out of lust. Boiling oil, hooks (nice long ones with sharp barbs on them) and their like are mentioned by several of the main characters. The quite civilised and cultured Sarabian is somewhat unnerved, asking them all if they have to be so graphic. He is told in no uncertain terms:
Kalten: Zalasta hurt Sephrenia, your Majesty. There are twenty-five thousand Pandion Knights -- and quite a few knights from the other orders as well -- who are going to take that very personally. Zalasta can pull mountain ranges over his head to try to hide, but we'll still find him. The Church Knights aren't really very civilised, and when somebody hurts those we love, it brings out the worst in us.
- In Dresden Files, although Harry is grown, and was his apprentice for only two years, Ebenezar McCoy is capable of this on occasion. In Summer Knight, he is so indignant that Harry is to carry out Mab's request without even knowing it that it takes Harry two tries to get through that, yes, he does know it. And he dropped a Russian satellite on the headquarters of a vampire who had threatened and fought with Harry.
- Eb's reaction is explained in the novel Changes: Ebenezar is Harry's maternal grandfather.
- What about Michael? He's a sword-wielding knight of God. He has a daughter who is about to be executed by the White Council Elders, who are powerful enough that even if you manage to kill just one of them, it would release a death curse which would be the magical equivalent of head butting the trigger of a 10-mega-ton nuclear warhead. He is exhausted and heavily wounded from battle. Yet, without the slightest hesitation, he immediately prepares to take them all on at once. Even knowing that afterward, should he somehow miraculously survive, he would forever more be on the run from every single white court wizard in the entire world.
- That was Harry. Michael, while he would certainly do that, simply had faith that God would help him out. Which he did, by zombie-dinosaur riding spell-slinging wise-cracking Honor Before Reason proxy.
- While we're talking about Michael, though... nine words. "That son of a bitch hurt my little girl."
- Harry also manifests this attitude toward Ivy.
- In Changes, the Red Court of vampires takes his daughter with the intent of sacrificing her to fuel a massive curse that will kill her entire bloodline. He responds by Joining forces with Mab and becoming her Knight, sacrificing two people on altars, and genociding the entire freaking Red Court. Don't fuck with Harry Dresden's family.
- He actually stated that if the world came between him and his daughter, it could burn to death and they would sit roasting marshmallows upon its roaring flames.
- Harry also serves as a surrogate Papa Wolf to the Carpenter family when Michael is otherwise occupied, as seen in the short story "The Warrior."
- Not to mention in Proven Gulty, when he teamed up with Mama Bear Charity to storm the freaking Winter Court in order to save Molly.
- Hell, he spends most of that book playing Papa Wolf to Molly, as her boyfriend would attest.
- An odd example from the series is "Gentleman" Johnny Marcone, the local Mafia boss who is essentially a Papa Wolf to every child in Chicago. If Marcone catches you doing anything to hurt children in his city, he will personally execute you. You don't want that.
- In Danny, the Champion of the World, it's revealed that Danny's father's main reason for disliking Hazell is because he threatened Danny. Later on, when Danny gets caned by his teacher, his father threatens to go down to the school and beat the teacher.
- Adrian Mole, upon finding that his little sister has been knocked up by her boyfriend.
- Becomes a major turning point in The Outsiders. Johnny stabs a Soc who was going to kill Ponyboy. Beware the nice ones, oh GOD Beware the Nice Ones!
- Let's not forget Dallas' reaction to Finding out Johnny was dying from his burns. Mind you, by this point the reader already knows how dangerous Dallas can be, but seeing him threaten to put the doctor in the emergency room for barring him access to Johnny's hospital room seems to be a bit of a case of Disproportionate Retribution.
- A slightly twisted variant occurs in Dexter By Design: Dex, of course, is already a Serial Killer masquerading as Just a Nice Guy, but it wasn't until relatively recently that he decided that he had feelings of love-ish for his stepfamily and foster sister (or, you know, anyone). So, when a rival slasher decides to mess with Domestic Daddy Dexter by stabbing Debbie and trying to kidnap his stepkids, out comes Deadly Defensive Dexter.
- Adam Hauptman, from the Mercy Thompson series. Bonus points for being a literal papa werewolf; mess with his daughter Jesse and you. Will. Die.
- The above also applies to Mercy. To make it worse, Adam runs a private security firm, so when he got worried about Mercy's safety, he installed an expensive security system in her house without asking her permission.
- Waylander the Slayer from the Waylander series of books by David Gemmell is a rather evil version of this. Having returned home from the war to find his wife and child killed, he spends the rest of his life and wealth hunting down the eight men responsible and killing them in ways that'd make even the most villainous of villains shriek.
- In Charlotte's Web the Gander threatens Templeton the Rat with serious bodily harm if he even thinks about bothering one of his goslings.
- One of the recurring themes in The Catcher in The Rye was Holden Caulfield's desire to protect children from the bad things in the world.
- There are some of these in the Star Wars Expanded Universe.
- In Shadows of the Empire, set some time before Return of the Jedi, the real villain of the book, Prince Xizor, does not get along well at all with Darth Vader. But they don't start to openly oppose each other until Vader finds that Xizor is trying to arrange for Luke Skywalker's death.
- By the time of a civil war between Corellia and what used to be the New Republic, Wedge Antilles is about sixty years old and has a pair of twenty-something daughters, Syal and Myri. Myri gets to stay with him on the Corellian side, where he spends about half of the series, but Syal is on the other side. And Wedge respects this, although it saddens him. He's very close to his daughters, and very protective of them.
Thrackan: "General Antilles, acting as Chief of State and Minister of War for Corellia, I hereby order you to communicate with your daughter Syal and do your genuine best to persuade her to follow whatever course of action I recommend to her. Is that clear enough?"
- Woe to you if you mess with anyone in Mandalorian Kal Skirata's biological or adopted family.
- Speaking of Mandos, Boba Fett in Bloodlines is this. So is Han. They team up.
- Speaking of Boba Fett, he was never a very good father (or husband), but he did his best to get close to his granddaughter, Mirta Gev. When he learns that a young Mandalorian is planning to marry Mirta, he gives his assent, but warns "Break her heart and I'll break your legs."
- This is part of the reason why Jacen Solo turned to the Dark Side and became the Sith Lord Darth Caedus, in addition to the Well-Intentioned Extremist trope: When he saw into the Pool of Knowledge and saw a man clad in Dark Armor (later revealed to be Darth Krayt) sitting on the Throne of Balance and seeing Allana, his daughter, standing by his side, he decided to become a Sith Lord in order to prevent that future from occurring, or at the very least prevent the part of the future where Allana is evidentially serving Krayt as his right-hand servant.
- Woe to you if you mess with anyone in Mandalorian Kal Skirata's biological or adopted family.
- Howl's Moving Castle is this after his son Morgan was threatened. He punched the guy twice. Not to mention his wife, Sophie is a Mama Bear also. In other words, don't mess with Morgan ever.
- Sadrao from Ursula Vernon's Black Dogs is not the protagonist, Lyra's, biological father, but he's a more than competent replacement after her real father is massacred along with the rest of her house. Sadrao's extremely Badass and is very protective of her, even going into a berserker-like rage when she's physically threatened.
- Caine. Even if you're a god, fucking with Faith will get your ass beat.
- Harry Potter: Dumbledore. Harm one of his students, and he'll return the favor.
- This is beautifully demonstrated when, being the Complete Monster that she is, Dolores Umbridge shakes Marietta Edgecombe violently in an effort to make her spit out enough info to get Harry expelled. Dumbledore magically pushes her away, jumping suddenly from calm and polite to highly angry. "I cannot allow you to manhandle my students, Dolores."
- This is also demonstrated when Barty Crouch, Jr. attempts to kill Harry after the Triwizard Tournament. Dumbledore doesn't take it very well.
At that moment, Harry fully understood for the first time why people said Dumbledore was the only wizard Voldemort had ever feared. The look upon Dumbledore’s face as he stared down at the unconscious form of Mad-Eye Moody was more terrible than Harry could have ever imagined. There was no benign smile upon Dumbledore’s face, no twinkle in the eyes behind the spectacles. There was cold fury in every line of the ancient face; a sense of power radiated from Dumbledore as though he were giving off burning heat.
- Papa Wolves are fairly prevalent in this series: Sirius Black does not like seeing Harry hurt, and neither does Remus Lupin.
- Mess with Draco Malfoy when he's at school, and the next person you'll have to deal with is his favourite teacher and godfather-of-sorts Severus Snape, or worse still, Lucius Malfoy, his actual dad, with the power of the school governors, as well as the Ministry of Magic behind him (and not to mention, Lucius's love for his family is pretty much his only good trait).
- Arthur Weasley, while usually overshadowed by his Mama Bear wife, in Deathly Hallows, threatened Kingsley Shacklebolt (trained Auror, later takes on freakin' Voldemort) to his face when he heard that one of his sons had been badly injured and Kingsley was trying to question him.
- Xenophilius Lovegood was ready to hand Harry to the Death Eaters if it meant having Luna back.
- And Harry's Uncle Vernon who- though he often falls into the categories of Abusive Parents (toward Harry, of course), Muggle and Bumbling Dad - is very protective of his own wife and son and is even willing to shield them from Hagrid.
- James Potter as well. It may not have worked, but he was willing to risk certain death against Voldemort if it gave Lily and Harry time to run. He would also do anything to help his friends in his school days, even if he was a Jerk Jock to everyone else at the time.
- Twilight: Jacob Black is a rather literal example (boy turns into a wolf) when it comes to Renesmee Cullen, the girl he's imprinted upon. Actually, this would apply to any wolf who has imprinted on a child.
- Don Pendleton's The Executioner series has Mack Bolan wipe out major crime families with dozens of thugs at their disposal after most of his family is killed due to the Mafia. When his girl-friend and younger brother are kidnapped by another crime family to try to get to him, he goes absolutely coldly berserk, terrifying even his friends and allies who have seen him in action many times.
- Matthew Reilly's Huntsman series. The adopted daughter of Jack West Jr. is threatened many times by many powerful people over the course of the books. Many people have died very graphic, painful deaths.
- In the Backstory of John C. Wright's The Golden Age, Helion had stayed on the Solar Array long past the point of safety to protect his son -- and his ship, but the priority was clear:
"Damn your ship." Helton's voice grated. "It was you. You were aboard at that time. Outside of the range of the Mentality, beyond the reach of any resurrection circuit."
- Catherine Webb's Horatio Lyle. He is not related to Tess or Thomas by blood, but hurt either of them and he will come after you with his pockets full of explosive chemicals, his home-made tazer, and, if all else fails, his frenzied but anatomically-precise application of teeth, nails, and knees.
- Robert Crais's Elvis Cole. Kidnap the son of his girlfriend? Elvis and his Psycho Sidekick Joe Pike will hunt you down to the ends of the earth and back again.
- In Aaron Allston's Galatea In 2 D, C. J. gets into the fight because his son is in danger.
- Good ol' Jim Davenport in Triggerfish Twist. Lets everyone push him around. But point a gun at his child and you will be very, very sorry, but not for very, very long.
- Rao is this to Shakuntala in Belisarius Series. As he was hired by Shakuntala's father to teach her how to be a Badass Princess, that would make her father an indirect Papa Wolf.
- Nastily subverted in Rick Hautala's The Mountain King. The protagonist sees his daughter torn apart and eaten by monsters, but is too terrified to leave his hiding place.
- In Death: Detective Sergeant Frank Wojinsky from Ceremony In Death. When his granddaughter Alice Lingstrom told him that she had been drugged and sexually exploited by an entire coven of Satanists and she had witnessed the leaders murder a young boy, he went Papa Wolf to try to take down the coven. Unfortunately, it made him sloppy and the leaders used the drugs Digitalis and Zeus on him, resulting in him dying of cardiac arrest.
- Marcus, of Time Scout, will go through hell for his little girls. So will Armstrong.
- As soon as he finds out Margo's his granddaughter, Kit becomes very protective of her. Skeeter, having tried to scam Margo before anyone knew, walks very, very shy around both ever after.
- The short story Monsters Tearing Of My Face has a particularly gruesome one. At the climax of the story, the little girl who drew the true picture of blue monsters tearing off her face turns out to really be a blue monster in a human disguise...when her mother tears it off of her, while her father tears the flesh from the bones of the foster parents who were about to rape her.
- Buster Beasely in 1635: The Dreeson Incident. "I'm coming, Princess Baby!" To the rescue, that is. And does he ever, on a Harley and with a .45 and a knife.
- Shellheart of Warrior Cats: Crookedstar's Promise is a Papa Cat, defending Crookedkit from his own mate. When she coldly tells him she blames her son for what happened to him, Shellheart is quick to defend him and breaks up with her. And when Rainflower tells Oakheart that Crookedstar would never be as good as him, Shellheart defends him with this:
Shellheart: Can't you keep your thoughts to yourself, just once?
- In Felix Salten's Bambi's Children (yes, it's that Bambi), he sees a poacher taking aim at his son, and attacks.
- In Tim Dorsey's novel Electric Barracuda it turns out that Serge Storms is a father. Hint to the child molester on the playground: you really don't want to try to entice the child of a serial killer.
- Charles Leeds, the husband and father of the second family of victims in Red Dragon, had his throat slashed in his sleep by Francis Dolarhyde. As he and his wife lay bleeding to death, Dolarhyde went down the hall to kill the children. With his throat cut open, artery spraying his lifeblood on the wall with every step he took, Leeds ran down the hallway after the killer and fought with him to protect his children.
- Aral Vorkosigan does this rather cleverly for Miles in Vorkosigan Saga. He convinces the council of counts to charge Miles with treason rather then raising a private army in The Warriors Apprentice, knowing that the penalty for both is death but actual treason was in fact impossible to prove(he was guilty of raising a private army; that is he got out of a tight situation by manipulating his enemies into defecting to him).
- Aral does this less subtly in Barrayar by ordering his private Heroic Sociopath, Bothari to protect Miles against Aral's own father. This caused an estrangement between them that lasted several years.
- Lieutenant Panga in Someone Elses War will do anything, absolutely anything, to keep the children around him safe.
- Atticus in To Kill a Mockingbird; not a violent man most of the time, but the way he uses his rifle makes Ewell hesitant to go near Jem and Scout. When he does, Boo Radley fills the role.