Gregor Clegane

"A man who sees nothing has no use for his eyes, cut them out and give them to your next outrider. Tell him you hope that four eyes might see better than two ... and if not, the man after him will have six."

- Gregor Clegane to a Lannister messenger

Ser Gregor Clegane is a character from A Song of Ice and Fire / Game of Thrones series.

He is the older brother of Sandor "The Hound" Clegane and is the head of House Clegane which are landed knights and bannermen to House Lannister. Gregor is a freakishly tall and large man, almost eight feet tall, and for this he is often called The Mountain That Rides or simply The Mountain.

He was originally played by guest star Conan Stevens in season 1, then replaced by Ian Whyte (in season 2) and later by Hafþór Júlíus Björnsson (from season 4 onward).

Personality
He's an infamous sadistic rapist and murderer. A silent short-tempered brooding man, who often asks for silence and time to stay alone. According to his squire, Joss Stilwood, Gregor constantly suffers from extreme headaches and consumes vast quantities of milk of the poppy to try and dull the pain. The cause of these headaches is unknown, perhaps due to some condition of his gigantism, though Merrett Frey's experiences indicate that a tourney injury or head blow in battle can be debilitating. This might be an explanation for Gregor's near uncontrollable temper. According to his brother, Sandor Clegane, Gregor once killed one of his own men because the soldier snored too loudly. Gregor's rage always overwhelmed his common sense, shown when he beheaded his own horse and nearly murdered Ser Loras Tyrell just because the latter defeated him in a joust, and for him to attack and fight Sandor when the latter stood in his way. Even as a child, Gregor was an irrationally violent person: he furiously burned his brother's face permanently just because the latter played with one of his toys without permission.

Abilities
The Mountain's skills are heavily associated with his incredible physical strength and herculean stature. He is so large and powerful that he wears the heaviest armor and weaponry in all of the Seven Kingdoms; a kind of armor so heavy that would make impossible for any man to move at all. Ser Gregor has gigantism and is known for his inhuman strength. He has arms and legs with the size of the trunk of a small tree and dwarves any known person. He was an exceptionally skilled swordsman, who was knighted for his accomplishments - which were augmented by his extremely violent and brutal fighting style. Gregor was, though, incapable of defeating his younger brother, Sandor, in a duel, because the latter was far more levelheaded than him. The Mountain possessed immense strength, and even as a boy, he outclassed his brother and it took three fully grown men to physically hold back Gregor.

Early Life
Gregor's history is dark and filled with blood. His father saw a true warrior in him, his brutality and strength caused to overshadow his younger brother Sandor. As a eleven or twelve-year-old, he caused Sandor's facial scars by holding the six or seven-year-old boy's face to a hot brazier as punishment for playing with a toy he had discarded, a gift from a man from the village of the Cleganes. As a child Sandor was always terrified by Gregor, implying he had already suffered his wrath before, and there was no true joy for him to play with the toy. He got caught by his brother who didn't say a word and shoved his face in the brazier. The men of the keep heard Sandor's screams, but it took 3 of them to pull off Gregor before he could completely burn Sandor to death. Their father spread the story that the injuries were caused by bedding that had caught fire and some years later some people started to believe that the burns came from a battle.

Four years later, he was knighted by Crown Prince Rhaegar Targaryen, a great honor. There were rumors that Gregor killed his father, sister, and his first two wives. His keep is said to be a grim place where servants vanish unaccountably and even the dogs are afraid to enter the halls. Gregor has committed rapes and cold blooded murders beyond count but his most infamous deed came from his service to House Lannister during Robert's Rebellion.

Aged 17, he was one of the first Lannister soldiers to enter the Red Keep during the Sack of King's Landing at the end of Robert's Rebellion. Lord Tywin Lannister needed a way to show Lord Robert Baratheon that his house was loyal to him and forsaken the Targaryens, so he instructed his men to deal with the royal family. Ser Gregor and Ser Amory Lorch scaled Maegor's Holdfast when the Lannister troops reached the Red Keep. While Lorch killed Princess Rhaenys, Gregor entered the nursery of the infant Prince Aegon, the son of Prince Rhaegar, and killed the baby by dashing the boy's head against a wall. Then he raped and murdered Aegon's mother, Princess Elia Martell, supposedly with the boy's blood and brains still on his hands. Ser Jaime Lannister had already cut King Aerys II Targaryen's throat, and did nothing because he thought the royal family was safe. Tywin was shocked by the brutal murders, as he wanted them to be clean deaths that wouldn't cause House Lannister to become more despised, instead the Targaryen children were a blood bath. Robert Baratheon was still pleased to see their bodies and smiled at their sight: their deaths was a relief for him, as the Lannisters spared to him the moral conflict of killing them himself and now his hands were clean. He still pardoned Lord Tywin and Ser Gregor for their crimes, earning the enmity of Dorne. Shortly after that, Gregor's father died and Gregor inherited Clegane's Keep and its lands and village. The same day Sandor left Clegane's Keep for Casterly Rock to serve House Lannister, where he became Cersei Lannister's bodyguard.

Ser Gregor fought in the Iron Islands, during the Greyjoy Rebellion. He followed King Robert I Baratheon and Lord Eddard Stark at the Siege of Pyke. Known people who fought beside him are Jorah Mormont, Jaime Lannister, Thoros of Myr, and Jory Cassel.

A Game of Thrones
Gregor rides to King's Landing where he takes part in the Tourney of the Hand, a tourney thrown in honor of Ned Stark's appointment as Hand of the King. In his second joust, he slays Ser Hugh of the Vale, piercing his throat with his lance. He also defeats Ser Balon Swann, but is eventually unhorsed by Ser Loras Tyrell, who purposefully rides a mare in heat in order to unnerve Gregor's stallion. Gregor flies into a rage, and kills his horse in a single blow before attacking Ser Loras. Gregor's brother, The Hound intervenes, and the two fight brutally before King Robert orders them to stop. He sullenly returns to his keep to brood on his defeat.

Upon his journey home from the tourney with seven of his men, Gregor still broods on his loss. An overflowing river detours the group to a nearby alehouse, where he and his men savagely gang rape the brewer’s 13 year old daughter. Her name was Layna; Gregor and his companions were drinking in silence, the men not daring to talk since Gregor was still in a bad mood. The old brewer kept saying how glad he was to have the Mountain and his band, due to the lack of customers because of the rains. Gregor loves silence and the Mountain's men never dare to speak when Gregor needs silence. The brewer even asks Gregor how his jousting went. Gregor keeps giving the brewer an angry look but doesn't say or do anything. Meanwhile, Eggon was drunk and started molesting Layna who was serving the group. Gregor pays no mind to this and stays quiet; when Joss puts his hand under her skirt, the girl shrieks, drops her flagon, and goes running in the kitchen. This would have simply ended there if it wasn't for the brewer's mistake to go to complain to Gregor and demands him to tell his men to leave Layna alone. Gregor was already upset and the old man's way to talk to him, a knight, cause him to order the brewer to bring Layna before him. He does so, perhaps believing that Gregor meant to apologize or something. When he sees her Gregor says: "So this is the whore you're so concerned for." The brewer replies: "My Layna is no whore, ser", and Gregor states: "She is now." He tosses the old brewer another silver coin, rips the girl's dress, and rapes there on the table in front of the brewer. The Mountain's men burst out laughing, while Layna's brother hears the noises and comes to intervene, but Raff the Sweetling stabs him in the belly. When Gregor is done he goes back drinking and lets his men have their turns on the girl, until she's broken and does not fight back anymore and lets them rape her. When they're done Gregor tells the brewer that he wants his change and that the girl wasn't worth a silver. The brewer begs pardon, gives Gregor his money, and thanks the men for the custom.

After Tyrion Lannister is kidnapped by Lady Catelyn Stark, Lord Tywin Lannister calls the banners of the westerlands and starts gathering a host at Casterly Rock. He orders Gregor to raid the Riverlands in order to draw Ned Stark into the field. Gregor's band, disguised as brigands, destroy the villages Sherrer, Mummer's Ford, and Wendish Town, where they kill the commoners and their animals, burn their fields, farms, and houses, and rape the women and the children before killing them as well. Tywin's plan fails however because Ned Stark had recently been injured by his son Jaime. Ser Edmure Tully sends Ser Raymun Darry, Ser Marq Piper, and Ser Karyl Vance to escort the survivors of Sherrer to King's Landing; there, In the name of King Robert, Eddard strips Gregor from all his lands and titles and sentences him to die. A vengeful Ser Loras Tyrells begs Ned to let him lead the party against the Mountain's men, but Ned chooses the stormlander Lord Beric Dondarrion over Loras and Ser Ilyn Payne to bring Gregor and his men to justice. He gives Beric many of his own Stark men in the royal party. Payne is genuinely offended by this, since this is supposed to be his job and duty.

With Lord Hoster Tully dying, his son, Ser Edmure Tully, tries to gather the banners at Riverrun, in order to fight the army of the Westerlands. But Gregor and the Mountain's Men make impossible for most of the river lords to leave their castles, so only part of the lords ride to Riverrun with their armies while the rest have to defend their people. After King Robert Baratheon's death, Ser Jaime Lannister's army defeat the river lords' army at the pass below the Golden Tooth and 2 Lannisters hosts invade the riverlands. Lord Beric's royal party fights against Lord Tywin and his army at the Mummer's Ford. Outnumbered, Beric retreats with the survivors only to be ambushed by Ser Gregor and his men, where Gregor personally kills Beric with his spear, and many other nobles, knights, and warriors die. After this, Tywin starts capturing castles and towns, including Raventree Hall, Harrenhal, and Maidenpool; meanwhile Jaime and his army defeat Ser Edmure's forcesat Riverrun and captured him, now besieging the castle thinking that Lord Hoster is not dying. Gregor leads his own forces and he burns the seat of the Pipers, Pinkmaiden Castle and its lands. Later he takes Stone Hedge, putting the castle to the torch, taking its food supplies, and burning the harvest of Lord Jonos Bracken. He then rapes one of Bracken's daughters. The Lannisters block the kingsroad and occupy the ruby ford over the Trident.

The Tullys are losing the war, now accused of rebellion since Queen Cersei rules in King's Landing now. With Lord Eddard imprisoned for treason, Robb Stark marches with his northern army to support House Tully, while the Vale of Arryn remains neutral but House Frey join with them. The Lannisters finally meet a stronger resistance and Ser Addam Marbrand's outriders face several skirmishes against Ser Brynden Blackfish, Lord Beric Dondarrion, and the parties of Lord Karyl Vance and Ser Marq Piper. Gregor joins Tywin's host camped on the Green Fork and fights the Northmen and the Freys led by Lord Roose Bolton at the Battle on the Green Fork. He leads the vanguard and commands Tyrion Lannister and the Vale mountain clansmen to hold the river. During the fight, his horse is killed by Karstark spearmen, but Gregor fights savagely, surviving as usual. The Lannisters manage to defeat the enemy, but it was actually Robb Stark's strategical plan to keep Tywin busy while his force draw out Ser Jaime's forces from the siege camps at Riverrun. The plans work and Jaime and most of his army is captured or killed at the Whispering Wood. Lord Tywin is so shocked about this that he fails to capture Roose Bolton, Robett Glover, and the rest of the surviving army who flee back to north.

Gregor sits on Tywin's war council when the westerlords receive word of Robb Stark's victory at Riverrun, defeating the rest of Jaime's army and freeing Edmure and his knights. Gregor is furious to learn about Jaime's capture and orders the scout to be punished by having his eyes removed. Tywin had underestimated Robb and was sure to defeat him so he could deal with Lord Stannis Baratheon. Instead King Joffrey I Baratheon executes Eddard Stark and causes a northern rebellion. With news of the threats of Stannis Baratheon and Renly Baratheon joining the war, the latter declaring himself king at Highgarden, Tywin decides to retreat to Harrenhal, while Ser Gregor remains behind to bleed the Riverlands along with Ser Amory Lorch and the sellsword Vargo Hoat. Ser Kevan Lannister personally instructs them do so.

A Clash of Kings
Gregor sacks several castles, burns down villages and harvests, and rapes and captures innocents. Harrenhal is a huge ruined castle with so many halls that it can host all of Tywin's army, Brave Companions, prisoners, and more. Robb Stark is now King in the North and the Lannister forces lose most of the places they took since the river lords are now stronger and the Brotherhood without Banners protects the smallfolk. Gregor and his men descend to Castle Darry shortly after it was liberated and akills the eight-year Lord Lyman Darry during the Sack of Darry, after Edmure Tully and Robb Stark let the lords of the Riverlands return to their homes. Having already killed  Ser Raymun Darry at the Mummer's Ford, the Mountain is directly responsible for the extinction of House Darry. After that he keeps causing large destruction in the Riverlands, and mercilessly burns villages in the name of King Joffrey I. He takes relief from his job by raping women and little girls, killing men and animals, and stealing food. The Lannisters, the Cleganes, and the Brave Companions however don't fight only against the rivermen and the northmen, instead they meet serious troubles with Beric's outlaws of the Brotherhood, who help the commoners to escape from the invaders and protect them from the cruelty of the noble houses.

In a raided town near the Gods Eye Ser Amory Lorch attacks a group of prisoners headed to the Wall. Many prisoners are either killed or captured, but a few groups manage to escape, including Arya Stark's small group. However Gregor and his Mountain's Men capture Arya's group in an abandoned village near the Gods Eye, because the fugitives needed to find food, and also medicine for their injured friend, Lommy Greenhands. First the Mountain's men capture Gendry and beat him, later they find Arya and Hot Pie, and Polliver takes Arya's sword, Needle. Then Gregor orders Hot Pie to lead his men to Lommy and a little girl nicknamed "Weasel". Lommy is killed by Raff the Sweetling, while Weasel manage to flee.

For a time, Gregor unwittingly held Lady Arya Stark in the riverlands, who swore to kill the Mountain after witnessing his many attrocities. Many commoners and sellsword are helping or even joined Lord Beric's outlaw band. As a result the people of the riverlands are all accused of being traitors and crown rebels. Gregor, Amory, and Vargo are instructed by Tywin to hunt down the outlaws and kill Beric, who became an hero of the people, unlike the Tullys or the Lannisters though Edmure took many refugees at Riverrun. Ser Gregor's captives are either tortured to death by the Tickler or are forced to serve House Lannister at Harrenhal. Gregor lets his prisoners be tortured, killed, and raped and doesn't stop his men; men, women, and children are tortured to death and Arya becomes scarred for life, terrified as a mouse. When she's forced to pee in front of everyone, Gregor and his men don't care if she's a girl. She survives her days with Gregor's band and finally her group of prisoners is given to Lord Tywin's garrison at Harrenhal, where Arya becomes the personal servant of a tower guard named Weese, who beats her bloody and humiliates her every day.

Gregor and his men soon go out to bleed the riverlands again. Ser Amory Lorch's party fight several skirmishes outside before bringing their prisoners at Harrenhal, including Jaqen H'ghar, Rorge and Biter. During the war Gregor's band, the noble knights, and the Brave Companions fight several skirmishes against the Brotherhood without Banners, and Gregor kills Beric Dondarrion for a second time. Beric keeps returning despite the fact that Tywin's men at Harrenhal reports him to be finally killed, instead he keeps returning.

When Ser Gregor returns to Harrenhal he keeps residence on Kingspyre Tower with Lord Tywin and his war council. Arya is scared of the 2 men, but she considers revealing Tywin her true identity because her time with Weese is too hard and she spends the night too far from the lords and ladies who are the only ones who keep civil order. To escape Gregor and his men Arya considers asking for help to the Frey captives, but they are soon ransomed. Arya considers revealing her true identity to Ser Wylis Manderly, Harrion Karstark, or Lord Medger Cerwyn, the latter who dies of his battle wounds. Gregor and his brother Sandor are on Arya's kill list along with Gregor's men Polliver, the Tickler, Raff the Sweetling, Chiswyck, and Dunsen. After hearing about what Gregor and his friends did to Layna in the past, she orders the Lorathi Jaqen H'ghar to kill Chiswyck.

King Robb's army invade the westerlands and destroy Ser Stafford Lannister's force at Oxcross, capturing many wester lords and knights, even Martyn Lannister. Lord Rickard Karstark kills Stafford, the northeners take several castles and mines, and Lord Galbart Glover invades the coast. King Renly Baratheon is dead and Robb plans to draw Lord Tywin out of Harrenhal so he can keep him busy in a pointless hunt in the westerlands until King Stannis lay siege to King's Landing and takes it. Tywin takes the bait, thinking that Robb is trying to take Casterly Rock and Lannisport and leaves Harrenhal, meaning to ride back to the westerlands and defeat Robb Stark there. Ser Amory Lorch is made castellan of Harrenhal and Vargo Hoat is instructed to destroy Roose Bolton's army camped on the road to Moat Cailin. Arya is upset upon learning that Gregor and his men are leaving since they are now out of her reach. She realizes she could have simply have Jaqen kill Tywin to assure Robb and Stannis's victories, instead Jaqen kills Weese.

Tywin, Kevan, Gregor, and Ser Addam Marbrand lead their forces in the riverlands, with Tywin trying to cross the Red Fork of the Trident. Ser Edmure Tully is made aware of Tywin's intentions and calls his banners, leaving Riverrun to engage Tywin's force, unaware about Robb's plan to drive Tywin and Gregor to the westerlands, so Stannis Baratheon can take King's Landing without meeting strong resistance.

Gregor and his men joins up with Tywin's host at the Battle of the Fords, where he loses against Edmure Tully at the Stone Mill. He's forced to retreat. Edmure and the river lords manage to force Tywin and his army to retreat as well. This costs dearly the entire war for both Stannis and Robb, as Tywin and his council receive the urgent news of Stannis Baratheon's fleet at Blackwater Bay, near King's Landing and manage to make an alliance with the Tyrells thanks to Lord Petyr Baelish.

Gregor's band remains in the riverlands. Harrenhal is taken by Lord Roose Bolton thanks to the betrayal of Vargo Hoat and the Brave Companions. Unawarer about the imminent northern attack, Arya, Jaqen, Rorge, and Biter help the northeners and Arya personally frees Robett Glover, who thinks she's working with Vargo. The Lannister garrison is killed by the northeners and Jaqen, and Roose Bolton has Ser Amory killed by Hoat's bear. After Stannis is defeated at the Blackwater, Roose sends Glover out again, before Arya can reveal him her identity.

A Storm of Swords
Stannis Baratheon is defeated and cut out from the war, hiding in Dragonstone. Tywin is now Hand of the King and prepares to end the northern rebellion, giving instructions for Lord Randyll Tarly and Ser Gregor to restore the king's peace in the riverlands. Gregor is disgusted when he learns about his brother who fled away from the battlefield during Stannis's assault and complains about him with his men, referring him as the "puppy".

Gregor and his host continue to fight many battles throughout the war, fighting the Northeners at Duskendale with Lord Randyll Tarly, where they kill Ser Helman Tallhart and capture Robett Glover and Harrion Karstark. After the battle he keeps fighting in the riverlands, while Randyll Tarly takes the town of Maidenpool. Since Robb plans to ride back to the north to fight the invading ironborn who took his lands in the name of King Balon Greyjoy, Tywin orchestrates with Lord Bolton, Lord Walder Frey, and Ser Rolph Spicer a plot that sees Robb and almost entire northern-riverlands host killed at the Twins during the "Red Wedding".

Gregor Clegane and his band start marching to Harrenhal, meaning to retake the castle and punish the traitor Vargo Hoat. In the Battle of the Ruby Ford, the band chase Lord Roose Bolton, who was riding with his host to the Twins for Edmure's wedding at the Twins, and take several highborn captives, including Ser Wylis Manderly. Roose flees and leaves (likely deliberately) another northern host behind to deal with the Mountain. Under the order of Lord Tywin he finally retakes Harrenhal from the Brave Companions, though most of them abandoned Vargo before the invasion. Gregor brutally slaughters nearly everyone in the castle, with a special torment reserved for the traitor Vargo Hoat. He cuts off his limbs, cooks them, and feed them to Hoat. There he and his men rapes repeatedly a girl named Pia who the Mountain smashes her face with a mailed fist for talking after he asked for silence. Gregor and his men hold the lands, while the Lannister and Frey armies besiege Riverrun and Raventree Hall and the Brotherhood without Banners keeps causing troubles.

After Tyrion Lannister is put on trial for the murder of King Joffrey, killed on his own wedding feast, and demands a trial by combat, Queen Cersei names Gregor as her champion. Gregor names Polliver castellan of Harrenhal and rides to King's Landing with Joss. Seeing a chance to avenge his sister Elia and her children, who were killed by Gregor and Amory Lorch, Prince Oberyn Martell volunteers to be Tyrion's champion. Tywin was originally going to put the blame on Ser Amory and refused to sacrifice Gregor for an alliance with House Martell, much to Tyrion's surprise.

The Mountain and the Viper fight, and Oberyn initially gains the upper hand, his speed and fighting style nullifying Gregor's greatest strengths; his immense strength and reach. Gregor gets and headache and gets more angry, bothered by Oberyn's constant talk about Elia and her children. He's toyed by the Dornish prince, who eventually manages to take Gregor down, but insists on having Gregor confess his crimes before dying. Oberyn gets too close, and Gregor knocks him down and crushes his skull, after confessing his crimes. He collapses as well, seriously wounded.

Despite winning the duel, Oberyn gets his revenge by having coated his spear with poison, drawing out Gregor's death and making it agonizing beyond belief. He screams so much that he can be heard screaming like a madman, his blood turning black, the pain unbearable, Gregor left with urine and excrement, and pleading for mercy kill. With Gregor's public confession in front of the Dornish nobles and knights that have now left the capital, Tywin Lannister has no other choice but kill him. Grand Maester Pycelle attempts to cure him, so that he can be executed to appease Dorne, but fails.

A Feast for Crows
Tywin is murdered by his son Tyrion and Cersei, Kevan, and Mace Tyrell have a power struggle. Gregor lingers on, and his condition continues to deteriorate. His blood turns black, his piss is full of puss and the Venom eats a hole the size of a fist in his side. His screams of agony are so loud that they wake people up in the Red Keep, prompting Cersei to have him moved to the dungeons below the keep, where Qyburn can experiment on him.

Gregor seemingly eventually passes, and a giant skull ostensibly his is sent to Dorne.

A Dance with Dragons
Gregor's skull is delivered to Dorne by Kingsguard Ser Balon Swann. Prince Doran Martell and the Sand Snakes are pleased to see it.

Meanwhile however, after being imprisoned by the Faith,  Queen Cersei sends word to Qyburn to replace the empty spot on the Kingsguard with one that would serve as her champion in a trial by combat. When she arrives at the Red Keep after her Walk of Atonement,  Qyburn unveils a new member of the Kingsguard to champion Cersei Lannister in her trial; Ser Robert Strong. He is an eight foot tall giant, the same size as Gregor, encased from head to toe in shining white armour. With Gregor's skull in Dorne, none can guess what lurks behind his visor. Presumably, he is the headless corpse of Gregor reanimated by Qyburn (who is believed to be a necromancer).

Robert is said to have taken a vow of silence, which is why he never speaks, but his brothers in the Kingsguard claim he neither eats, sleeps nor shits either. Many in the Red Keep have guessed the silent giant's true identity, including Ser Kevan Lannister, Lord Mace Tyrell, and Lord Randyll Tarly. Kevan makes clear to the small council, however, that it is in everyone's best interests that Strong's identity not be questioned and that he must prevail in Cersei's trial. If Strong failed and Cersei was found guilty, Tommen's legitimacy as King and, thus, Margaery Tyrell's status as Queen would be thrown into question, hurting both the Lannisters and the Tyrells.

Character and Appearance
Gregor Clegane's size, strength and cruelty are things of legend in Westeros. He is extremely tall, almost eight feet, and weights 420 lbs (190 kg) all of it pure muscle. He wields a six-foot, two handed great sword in a single hand, giving him enormous reach, while still affording him the protection of a shield. He has been known to hack men in half with a single blow.

When in battle, he wears the heaviest armour known to man, so thick and large that no other man can so much as move let alone fight in it. Below it, he wears chainmail and boiled leather, and sports a plate helm emblazoned with a stone fist punching towards the sky. He carries a massive oaken shield emblazoned with the three hounds of his house. These accountrements make Gregor virtually invincible on the field of battle.

Gregor's size appears to be caused by some form of gigantism. A side effect of this are constant debilitating migranes. This appears to be the cause of Gregor's perpetually foul temper. To make his condition bearable, he consumes great amounts of milk of the poppy, to the extent that he has built up a sizeable immunity to its effects.

Gregor is known for his violence and cruelty. He is a sadistic murderer and rapist, and takes great pleasure in tormenting others. His foul temper makes him a danger to all those around him, and he once supposedly killed a man for snoring to loud. He has been compared to a frothing dog. Gregor is very solitary, and never leaves his lands unless he is fighting in a tourney or a war.

Trivia

 * Gregor is often viewed as one of the six most evil villains in Game of Thrones, other five being Ramsay Bolton, Joffrey Baratheon, Walder Frey, Karl Tanner and Craster.
 * He is also considered one of the ten worst villains in the original A Song of Ice and Fire novels and its spin-offs, with other nine being Aerys II Targaryen, Craster, Ulf the White, Hugh Hammer, Joffrey Baratheon, Ramsay Bolton, Euron Greyjoy, Maegor I Targaryen and Rorge.
 * Although Gregor rarely speaks in the novels, in the adaptation TV series, his character is more silent during the story. This is due to the fact that he was first cut from the last two episodes of the first season, then played by actor Hafþór Júlíus Björnsson, who does not speak English well, so his lines are simplified. Thus, the Mountain is heard to speak longer sentences only in the second season.
 * In the TV show Ser Robert Strong still has his head, unlike his book counterpart. When he is presumably reintroduced as the apparently-zombified Ser Robert Strong, his eyes are seen through his helmet with pale greenish flesh.
 * In the TV show, the "Robert Strong" persona has never mentioned in this name, yet the ending credit confirms this mute knight is in fact Gregor in disguise, also portrayed by Hafþór Júlíus Björnsson. This has possibly clarified a highly possible theory that Gregor and Robert Strong are one and the same.
 * During A Dance With Dragons occurs, Gregor was still on Arya Stark's list of people who she tried to kill even after his alleged "death", for Arya had no idea that Gregor died and thought he is still alive. This is also implied in the TV series.