Ever since his introduction, Ser Gregor Clegane, better known as "The Mountain That Rides" or simply "The Mountain," has cemented himself as one of the most terrifying characters in Game of Thrones. First played by Conan Stevens in season 1, before the role was recast with Ian Whyte for season 2, and then recast again with Hafþór Júlíus Björnsson playing the character from season 4 onward, Ser Gregor's reputation as a ruthless brute proceeds him. The combination of his strength and ferocity makes him seem like one of the deadliest foes in the Seven Kingdoms.
However, Game of Thrones cleverly conceals a secret about the Mountain. This small detail about the character, hiding in plain sight, makes him feel far less threatening. Despite how Game of Thrones portrays him, Ser Gregor is far from infallible.

The Mountain only ever wins one on-screen fight in Game of Thrones
Ser Gregor first appears in the Hand's tournament in season 1. Thanks to rigged lots, he initially faces off against Ser Hugh of the Vale (Jefferson Hall), the squire to the late Jon Arryn (John Standing) who earned his knighthood after the former Hand's death. During the joust, the Mountain brutally kills Ser Hugh when a piece of his lance breaks off and lodges itself into the fresh knight's throat. Conveniently, this silences Hugh, the one man in King's Landing who may have additional information about Jon Arryn's mysterious death.
This marks the last time the Mountain actually wins a fight on screen. The legendarily cruel knight manages to lose the rest of his major duels throughout the series. Shortly after his joust against Hugh, Ser Gregor finds Ser Loras Tyrell (Finn Jones) as his next opponent. Ser Loras wins by riding a mare in heat, successfully distracting Ser Gregor's horse. Ser Gregor then immediately loses another fight after decapitating his mount and heading for Loras before the Mountain's younger brother, Sandor Clegane, better known as "The Hound" (Rory McCann), defends the Knight of Flowers, holding his big brother back long enough for King Robert Baratheon (Mark Addy) to stop the fighting. The Hound is clearly depicted as the superior warrior during this brief brawl.
The Mountain's next major fight takes place in season 4, when Queen Cersei Lannister (Lena Headey) calls on him to represent her in a trial by combat to condemn her younger brother Tyrion (Peter Dinklage), aiming to prove his guilt in the murder of King Joffrey Baratheon (Jack Gleason). Although the Mountain infamously and brutally kills Tyrion's champion, Prince Oberyn Martell (Pedro Pascal), he loses the actual fight against the Dornishman. After Oberyn knocks the Mountain down, he attempts to goad his foe into confessing to the murder of his sister, niece, and nephew. Oberyn's overconfidence ultimately costs him the fight, and his life, but not before he successfully defeats the Mountain in combat.
Finally, the Mountain faces off against The Hound in a duel which fans call "the Cleganebowl." The brothers' climactic showdown takes place during Daenerys Targaryen's (Emilia Clarke) assault on King's Landing. The two mortal enemies lock eyes as the Red Keep falls apart, and face off amid the chaos and carnage. After his revival by Qyburn (Anton Lesser), the Mountain feels extra resistant to the Hound's attacks. Sandor is ultimately able to outsmart Gregor by jumping at him, knocking them both off the tower of the Red Keep and into the flames below.

Why is Ser Gregor still so scary?
Despite his on-screen losing streak, the Mountain is still able to "aura farm" thanks to his off-screen victories, as well as his sheer displays of strength. Throughout the show, audiences are told of the Mountain's great victories. For example, early in the show's run, the Mountain is reported to have been raiding the Riverlands, and viewers later hear about how he is able to easily defeat and kill Beric Dondarrion (then played by David Michael Scott before Richard Dormer takes over the role in season 3 and beyond), the man Ned Stark (Sean Bean) sent to bring Ser Gregor to justice. Beric's demise helps paint the picture of the Mountain as a terrifying warrior, but it takes place off screen.
Additionally, the Mountain chooses his opponents well, often targeting unarmed civilians and killing them with his might rather than actively engaging in battle. During Arya Stark's (Maisie Willaims) time at Harrenhall, Ser Gregor's sheer intimidation is able to keep the prisoners in line, he never actually harms any of them himself. From then on, he is usually seen attacking unprepared foes, especially after his rebirth. In Cersei's service, he kills several of her opponents, including many members of the Faith, with his raw strength, rather than with any combat prowess.
As Bronn (Jerome Flynn) predicts when describing how a fight between him and the Mountain would play out, Ser Gregor is a beatable opponent, so long as his enemy fights carefully and thoughtfully. He relies on his fear factor, brutality, and brawn to scare his enemies, but in reality, he isn't as great a warrior as several other characters depicted throughout the series. Despite his constant on-screen loses, Game of Thrones is still able to portray the Mountain as a terrifying, indomitable opponent, making it seem like characters overcome impossible odds when they're able to defeat him.
For more from the world of Westeros, make sure to stream House of the Dragon season 3 on HBO Max.
