The Adventures of Teebo: The Gruddak is big enough to pick up an Ewok in its hands, but, despite being accused of being a kidnapper, is a kind-hearted guardian of the forest.
The Hork Bajir in Animorphs qualify. Despite being 7 feet tall, covered in blades, and being used as alien brain slugs' foot soldiers, they have no aptitude for fighting and use their blades to slice and eat tree bark.
Roald Dahl's title character in The BFG. All the other Giants are monstrous Child Eaters though. Somewhat subverted when you consider that by Giant standards, the BFG is very small.
Battle Royale: Hiroki Sugimura is the tallest student in class and practices karate, but he's also a quiet and reserved Martial Pacifist who only fights if he has to.
Black Dogs: Gunnar, a 10 foot tall anthropomorphic giant ground sloth, is very calm and placid, but can be provoked to violence. He often acts as the voice of reason to his extremely aggressive and bloodthirsty companion Spite, who is an anthropomorphic weasel and about three feet tall.
Stephen King's Blaze; the titular character is a big, mentally challenged con man who kidnaps a millionaire's baby for ransom. It's not before long before he begins to bond with the child.
Ben Colm in the Daring Finds series. Six-foot-three and built like a tank his best friend, Candyce Dare has never seen him lose his temper even though the first time they met, in seventh grade, he rescued her from three bullies. As she describes it it wasn't really a fight, he just walked over calmly, extended his fists and the bullies just ran into them.
Dinotopia is a Utopia with peaceful dinosaurs. Go figure. The largest ones are explicitly the most careful around smaller beings, to the point where they can safely play with young humans by flinging them into water or annihilating them at tug-of-war.
Many civilized trolls adopt a Gentle Giant demeanour when dealing with other, more breakable races, but mostly out of convenience, not niceness. One member of the City Watch, though, a troll constable named Bluejohn, is the largest the commander of the Watch has ever seen, much bigger even than normal trolls, and "like many big people" is really quite gentle and diffident. He's so massive and tough he can function as an impromptu riot shield for a squad of coppers. However, this is by no means universal, as plenty of trolls find employment as hired goons, and there are more than a few troll criminal masterminds who operate out of the meat refrigeration areas.
Also, Captain Carrot is six-feet-six, broad-shouldered, and immensely strong due to growing up in a dwarven mine, but he's just about the nicest guy you'll ever meet. In early books he avoids fights altogether because a lot of people take one look at him and decide maybe having a go at him isn't a good idea; in later ones his incredible charisma does pretty much the same thing.
Lady Sybil Ramkin is an unfailingly polite and gracious Valkyriesque dragon breeder who, by the fact of being large and kind, is sometimes misinterpreted as being "stupid" (or "deaf").
Constable Dorfl is a golem, and has chosen to be nonviolent. So far he is also quite possibly the strongest person/thing on the watch, as golems have been described as capable of ripping trolls in half. While golems in general are this way because they have the functional equivalent of the Three Laws embedded in their heads, Dorfl does not, and is very specifically nonviolent by choice alone. When he was first "freed" he went around and exacted revenge on a number of his former masters. But the worst he did was dress up a slaughterhouse owner with an apple in his mouth and a carrot "somewhere else", and free all the animals.
Jason Ogg, son of Nanny Ogg and Lancre's premier blacksmith, is huge and strong (so that it is hard to believe he was born and not, say, constructed), and definitely a gentle giant, though this doesn't stop the local pub owner from calling on him to break up drunken brawls by knocking the combatants together "in the friendliest way possible": holding one of the combatants off the floorin each hand, then knocking their heads together.
Ludmilla Cake in Reaper Man, a rather diffident Wolf Woman who even in human form appears to be built to a larger scale than everyone else and is described as one of those people who goes through life in a crouch in case they're accidentally looming at people.
Constable Precious Jolson, a minor Watch character, is described as a large, cheerful, always smiling woman with the muscles of a troll.
Brutha in Small Gods isn't quite a giant but is known to his peers as The Big Dumb Ox and could, if so inclined, break the Lean and Mean Vorbis with his bare hands. He also has such an aversion to violence that he can't bring himself to even let Vorbis fall into a trap despite knowing how evil and dangerous the man is.
Al from Divergent is much bigger than everyone else, yet is so afraid of hurting others he refuses to fight during the first phase of initiation.
Don Quixote: The giant Morgante is one of Alonso Quixano’s favorite characters, because despite being a giant (and in the chivalry books all giants are arrogant and angry), he is affable and well bred… The whole point is that Alonso Quixano thinks this kind of character is original to his beloved chivalry books, but really it’s not. This trope was a cliché even when Don Quixote was written, in 1605, as we can see in Part I, Chapter I, Alonso Quixano:
"… approved highly of the giant Morgante, because, although of the giant breed which is always arrogant and ill-conditioned, he alone was affable and well-bred."
Father Roche in Doomsday Book is a gentle, meek and almost inhumanly patient Good Shepherd. Kivrin describes him as having enormous hands and the Face of a Thug. Late in the book she remarks how tiny she is compared to him.
Harry Dresden is, by his own description, NBA tall, being a little bit short of 7 feet tall. He's not particularly bulky, but is generally in quite good shape, usually has a gun on him, and eventually gets a decent amount of hand-to-hand and staff fighting training in as well. He's also one of the most powerful Wizards on the planet with a penchant for fire magic and has been scrapping with Dark Wizards and supernatural monsters since he was a teenager. He has no problem with killing if the situation warrants it, extending to an act of complete genocide. In short, people who cross him have a tendency not to survive a whole lot longer. He's also a total dork, a massive nerd and a Friend to All Children. When all is said and done, he's happiest making cheese jokes, hanging out with his friends and playing tabletop role playing games, reading books, going to drive-in movies or researching the Art (magic).
Harry's dog Mouse is much like his master. He's nearly four feet at the shoulder, weighing in at 200 something pounds and is also a magic foo-dog apparently powerful enough that an Archangel refers to him as "little cousin" and his mere presence terrifies a Fallen Angel. If there is not threat, however, he becomes a goofy, adorable fuzzbucket whose great delights in life are scritches, people food and rides in the car. He has even managed to melt the hearts of people who are phobic about large dogs. Due to his Magical nature, Harry suspects Mouse is far actually very intelligent (and he's almost certainly correct).
Harry's friend and Knight in Shining Armor Michael Carpenter also counts. He's only a bit shorter than Harry and significantly more muscular and wields a holy sword (that may or may not be Excalibur) as a Knight of the Cross, meaning he basically goes around the world fighting Fallen Angels and saving people, at least when he isn't at his day job as a carpenter. He's also probably the single kindest person Harry knows, a loving father, great friend and generally all around good man, as evidenced by the fact that the Archangel Uriel considers him a personal friend.
Harem in the Labyrinth of Another World: Vesta is the largest member of Michio's harem, due to being Dragonkin. She's also the sweetest and most docile of them all.
In the Horus Heresy novels, Vulkan, Primarch of the Salamanders, stands head and shoulders above even the other Primarchs, who are giants by normal human standards already. He's also an All-Loving Hero who hates violence and once managed to get The Stoic Rogal Dorn to crack a smile with a spontaneous hug. His huggyness has become a minor meme in the Warhammer 40,000 fandom.
In Hurog, the protagonist Ward is this. Heis a very kind person, who is protective of his younger siblings and pretty much everyone who is there to be protected. He is described as having the stature of an ox by less nice people, and nicknamed "giant of [his homeland]" by nicer ones. He mainly uses his size advantage to carry wounded people and animals, or protect people by simply being there and looking intimidating. His father averts the trope by being the tallest man around, and a jerk.
The Edge Chronicles gives us an entire species of these in the banderbears, who stick out all the more in the Deepwoods. So long as you don't mess with them, they're affectionate teddy bears who happen to be the size of grizzlies (and have sharp tusks). When Twig has an Androcles' Lion moment with one in the first book, he ends up befriending the lot of them by extension — generations later, they remember the word "friend" he taught them.
Sea Serpents described in Fantastic Beasts and Where to Find Them can grow up to 100 feet long (to a Blue Whale's 98) but there is no record of them ever harming a person, or in the author's opinion, no credible record.
The Giants in Guy Gavriel Kay's The Fionavar Tapestry are so pacifistic that they won't fight back against people actually killing them. The reason is complicated, but it involves an ancient curse.
From Glen Cook's Garrett, P.I. series we have seven- (or nine, if you ask Garrett) foot-tall imposing black man named Playmate, who does not have "a mean bone in his body" and Saucerhead Tharpe who, while earning a living as a strongarm specialist, is very civil to the people he knocks out.
Girl Waits With Gun tells the story of Constance Kopp, A hulking farmgirl who only wants people to leave her family alone.
Goblins in the Castle: Literally in Goblins on the Prowl with "Bonecracker" John, a giant who is actually quite nice, but has an undeserved reputation as a result of his having badly injured a knight once.
The titular character of Good Dog, Carl! is a Rottweiler who babysits a little girl named Madeline.
Joe from Charles Dickens's Great Expectations fits this trope. He doesn't hurt anyone, except Orlick who he knocks out in one punch after Orlick kept insulting his wife.
Rubeus Hagrid is a kindly half-giant, though he'll get angry if you insult Dumbledore, Harry, or anybody else he cares for.
Though he's very much not one in his first appearance, Grawp, Hagrid's half-brother, learns by Hagrid's patient and determined example to be a Gentle Giant, at least when dealing with people. If the people he cares for are hurt or killed, he is the first to utterly break down crying. He's much more tender and caring than any of the main characters.
The Giant Squid living in the Hogwarts lake seems to be a friendly monster — it's first introduced putting an overboard student back in the boat, and Fred and George have been seen tickling it. Although Harry still hopes not to see it when he swims in the Hogwarts lake.
In their native home, the Hyperborean giants are peaceful. Percy and Co. still use one to help them escape from some griffins.
Tyson also technically counts.
Damasen, as the opposite of Ares, is the most benevolent of the Giants.
The In Death series: Leonardo is very much this. Dr. Mira even refers to him as such in Vengeance in Death. Crack can also be, as long as you don't piss him off. Then he becomes a Scary Black Man.
Iomhar from The Last Human Getaway is a large, purple troll living in the wilds of the Scottish Highlands. Due to his appearance and past hostilities, he's very timid and tends to end up by himself most of the time. He bonds with protagonist Annie due to their artistic abilities. When he realizes the villain is trying to sacrifice both her and her Love Interest Yves, he starts grabbing rocks and hurling them at the invading evil faerie creatures, before dissolving into Inelegant Blubbering when the fight is over.
The Ents of J. R. R. Tolkien's The Lord of the Rings are, like trees, stolid, slow to move, and strong enough to crack rocks. They're eventually rallied into war, but it takes a lot of talk.
The Lonely Troll in the poem of the same name qualifies. Unlike most trolls, he doesn't steal gold, drink beer, or eat meat, but everyone's scared of him. To the only person who isn't scared, he teaches the secret of making the best bread anyone ever baked.
The protagonist of Lone Huntress is a rare female example. Lisa is over six and a half feet tall and looks like a fetishistic muscle goddess outside of her Powered Armor. Inside her suit she resembles a cyberpunk Grim Reaper, particularly for Space Pirates. In fact she's a young woman with deep seated issues and crippling loneliness. She gets better. Eventually.
Hammond from Mistborn: The Original Trilogy. He's a big burly man, and furthermore is a Pewterarm, or as they are more commonly known, a Thug. He's also Happily Married (the only protagonist to be so for most of the series) and loves to debate philosophy with anyone who's interested. Or who can't run away.
Lauchlan from Mix Beer With Liquor And You Will Get Sicker is described as being 6' 2" tall, broad shouldered and having prominent facial scarring, and is soft-spoken and kind-hearted to a fault. He adores the draught horses he cares for, and will normally put their own needs before his own. Same with his cat.
Queequeg is a pretty intimidating guy: tall and strong, decked out in tribal tattoos, has filed-sharp teeth and a partially shaved head, and is always seen toting around his beloved harpoon. Ishmael is initially terrified of Queequeg, but becomes fast friends with him after discovering how kind and polite he really is.
Also many of the whales are portrayed as such, only fighting back when the whalers strike first.
Mr. Tall in the Mr. Men series, though he's only a giant because of his long legs. He is very self-conscious about his height, and has to be convinced by the other characters that it has any advantages.
In Robert Asprin's Myth Adventures series, one of the members of M.Y.T.H. Inc., is Chumley, a huge green-furred troll. Although he works as muscle-for-hire under the persona of 'Big Crunch,' he's actually the most erudite and poetic of the M.Y.T.H. Inc. crew.
The Giants in C. S. Lewis's Narnia are usually depicted as dumb or evil (especially in The Silver Chair), but in the second book (The Lion, the Witch and the Wardrobe) we meet a very gentle and polite one: Rumblebuffin, who was Taken for Granite by Jadis the Witch especially because of this. Aslan revives him and he joins the cause of the Pevensies immediately.
The Giants in The Silver Chair are ironically the ones referred to as 'Gentle Giants'. While they are far gentler and more refined then their brutish cousins, few of them show qualms against eating weaker, sentient beings.
The literary archetype for this sort of character is probably Lennie in Of Mice and Men, by John Steinbeck. Averted shockingly at the end when he assaults Curley's wife (after she lets him touch her hair, then panics) and flees into the countryside. His travelling companion George follows him and shoots him dead to prevent the posse lynching him instead. It's also strongly implied that this is not the first time Lennie has done something of this sort. Although he's more of a subversion of the whole "gentle" part, seeing how many animals he kills by accident.
Adzel in the Polesotechnic League series by Poul Anderson. He's a sort of huge mix of a dragon and a centaur, he looks like a bloodthirsty scaly monster, yet he's a pacifist scholar following the buddhist doctrines. You can't blame him for his size, after all.
Fezzik from The Princess Bride. His backstory mentions that he can rip a tree up by the roots, but he's scared of the bugs that live among said roots.
The gorilla-like Blue-haired men from Quest for Fire. The protagonist observes how they are big eough to conquer all other tribes of men but like real gorillas, they are content to live a peaceful vegetarian existence in the forest provided they are undisturbed.
Orson in Record of Lodoss War. When he is not in Berserker mode, he comes across as a fairly gentle, soft-spoken person... although he is also a very emotionless character (for a good reason, as he is possessed by a spirit who has deprived him of all his emotions except rage).
Red Country: Subverted by Lamb. Shy notes that the hulking man may be the most timid and cowardly person she's ever met. He spends all his efforts working the farm and being a tender Parental Substitute for her and her young siblings. However, it turns out that he's actually a retired Logen Ninefingers, the most violent and bloodthirsty bastard in the North, and perhaps the whole world. When circumstances turn desperate, he reveals that he can and will kill anything that moves.
In Roger Zelazny's novel Roadmarks, Mondamay is a large alien robot with the power to obliterate entire planets, but finds himself left behind by his creators due to a malfunction. He becomes a potter and lives a peaceful life until reactivated by an assassin and ordered to kill a friend.
Subverted in the Septimus Heap series with the dragon Spit Fyre, since while he's depicted as being rather gentle in the first books, in Darke it's mentioned that he nearly ate a person who had run into his Dragon House for a dare.
Longinus Podbipięta from With Fire and Sword is huge, carries a BFS his ancestor got at Grunwald, but he's only sent on a mission against brigands once, since he just let all the captives go. Which wasn't the point, understand. He's also eternally patient towards his snarky friend, Zagłoba and adorably shy around ladies.
Hodor is almost seven feet tall but has the mind of a young child. He's timid, frightened easily, and completely incapable of defending himself.
Brienne of Tarth stands at roughly 6'6" and a lean 250-300 lbs, and has a keg-shaped head, a barrel chest with thick, rippling pecs and narrow hips instead of teats and curves, shoulders so wide and heavy with muscle that they are "hunched" under their own weight, a bull neck, and hands and feet so enormous they are comparable to Gregor Clegane's in size and shape. She's also one of the sweetest, most kind-hearted characters in the series, unswervingly loyal, and truly lives up to the ideals of knighthood despite not actually being a knight.
In The Sorceress's Orc, orcs in general tend to be this. They look like stereotypical orcs, big, broad and with dangerous teeth, but aren't more aggressive than humans, rather less. The titular orc, who is the sorceress' bodyguard, mentions that his parents wanted him to become a smith and were rather disappointed when he chose to become a mercenary. Despite his career choice one doesn't get the impression that he is fond of killing people, and it often happens that his employer gets more obviously angry at the anti-orc racism than he does.
Space Glass has Bob Balter and Bagok Grinch, although Bagok more so.
In Lois McMaster Bujold's Historical FantasyThe Spirit Ring ones first impression of Thur Ochs is that he is a very large young man, and quite strong—when he reached his current height and strength "everyone spontaneously began assigning the heaviest tasks to him". However, while Thur is by no means a coward (one of the first things we see him do is risk his life to save men trapped in a mining cave-in) he has no desire to be a soldier, not because of the risks to himself but because he hates the thought of sticking a sword into another human being. His first reaction to anyone he meets (even kobolds, considered by many in the setting to be basically demons) is to be friendly. His body language tends strongly towards the nonthreatening—he often hunches his shoulders or stoops down a bit so as not to loom so much.
In Stephen King's The Stand there is the character of Tom Cullen: a big, strong, friendly man with a mild case of mental disability. Tom is so gentle that he would never dream of commiting violence, and possesses a child-like sense of innocence and wonder.
Temeraire: The dragon Kulingile hatches as a deformed runt and develops a quiet, shy, gentle personality, which he retains even after growing to become the largest dragon in Britain. However, when his Dragon Rider or the rider's brother is threatened, he becomes an unstoppable force of destruction.
Boo Radley from To Kill a Mockingbird Throughout the majority of the novel, the kids have no idea what he looks like, and fear him greatly. The simple act of touching his house is a feat for them. But in the end, he's revealed to be a nice, timid, harmless man, as he saves Jem from Bob Ewell (albeit by killing him) and makes his appearance known. (Although, in the film version, he's really not so big.)
In P. G. Wodehouse's Ukridge stories, Wilberforce Billson defaults to this. Ukridge sees Billson's potential as a boxer, and tries to make a bit of money by managing him in the ring, but in "The Debut of Battling Billson", Billson lets himself be defeated out of sympathy for his opponent's hard-life story, and in "The Exit of Battling Billson", Billson refuses to fight at all on religious grounds. If provoked to the point where he loses his temper, however, it's a different story — in "The Return of Battling Billson", he demolishes his opponent (although this is no comfort to Ukridge, who had wanted him to take a dive that time).
The eponymous character in Uncle Styopa by Sergei Mikhalkov is so tall he can easily reach telegraph cables with his hand, and he is an incredibly kind man with a serious case of Chronic Hero Syndrome, saving a little kid from drowning, a train from derailing on a damaged railway, and a flock of birds from a fire (and these are only his most famous moments). It's because of his eagerness to help everyone in need that he eventually joins the navy and after that the police force.
In The Wanderer and The Adventurer by Mika Waltari, Antti the Cannoncaster is almost superhumanly strong, and very tall. Despite sometimes accidentally breaking things (sometimes people's necks, for example...) he is not violent by nature and is, all things considered, a somewhat docile person. The protagonist/narrator thinks him dumb as well, but the reader may well disagree, as he can both use his incredible strength as a means of subtle threats, and can think on his feet very admirably. At some point one starts to wonder whether he prefers to keep up a facade of stupidity to get into less trouble, but he might just refuse to keep up a facade of intelligence like the narrator, Mikael, does. As a character, Antti is very The Lancer-like, and sort of a Straight Man to the sometimes Cloud Cuckoo Lander protagonist.
In Simon Spurrier's Warhammer 40,000Night Lords novel Lord of the Night, Cog. As long as Mira isn't threatened and you don't call him an ogryn.
A Rare Female Example is Stephen Gordon from The Well of Loneliness, who is as tall, broad-shouldered, narrow-hipped, and barrel-chested with muscle as her father (who himself is a big man), but also extremely self-conscious.
The Ogier are an entire race of gentle giants, though not those in the service of the Seanchan. An in-universe saying is "to anger the Ogier and bring the mountains down on your head." To most people, this is taken to mean that it's impossible to get one mad, but to the Seanchan, it's more a warning that it's suicidal to do so. Both interpretations are correct.
Perrin is characterized like this at the beginning of the series, but it shows up less as he takes on more responsibility for protecting people.
In With a Tangled Skein, this is discussed and justified. In the aftermath of a fight, Cedric is talking with the dean of his school, and the dean reminds him that since he's a big, muscular guy, he's got to be extra careful not to intimidate or bully people with his strength. This is after he stopped a gang of his fellow students from raping his wife; he still had to let them get the first punch against him before he retaliated, and he was still worried that he might have killed one of them.
Longinus Podbipięta from With Fire and Sword. He fits the Giant part because he's a two meter tall Lithuanian toting a BFS so heavy no one else can wield it in combat. And he fits the Gentle part because he's friendly and loyal unto death to his friends but Tranquil Fury for his enemies. When he was young, he made an oath that he won't walk to the altar with a woman until he repeats something one of his ancestors did (decapitating three heathens in one swing) in order to prove himself worthy of his name.
In Ken Follet's novel World Without End, Mark Webber, the Kingsbridge weaver, is regularly described as a gentle giant.
The Japanese children's book Yasashii Lion (The Kindly Lion) by Takashi Yanase is about Buru-Buru the lion who was adopted by a female dog named Muku-Muku after the death of his parents as a young cub. As a grown lion, he's very sensetive and gets his feelings easily hurt. Such as bursting into tears after seeing his own reflection in a lake thinking he was a dog and calling himself ugly. Thankfully, Muku-Muku quickly calms him down by saying "You and I appear different indeed, but in our hearts, we are the same." since she strongly believes "The heart is the most important thing" between a mother and son.
Lowbacca from the Young Jedi Knights series is Chewbacca's nephew and a promising Jedi apprentice. Like his uncle, he's huge and intimidating, but is actually uncomfortable and shy when he arrives at the Jedi Praxeum, being unfamiliar with everyone. He takes to going off into Yavin IV's jungle alone until the Solo twins get him to open up to them.
