Gregor Clegane

Ser Gregor Clegane was the former head of House Clegane and the older brother of Sandor and Jeyne Clegane. As a large, strong and lethally skilled knight, he quickly became known as "The Mountain That Rides" or simply "The Mountain". During the War of the Five Kings, he headed a band of raiders, and later a full army, to reave and pillage the Riverlands at the behest of Tywin Lannister. During the second trial by combat of Tyrion Lannister, he was fatally poisoned by Oberyn Martell, but was saved from death by Qyburn. Qyburn's treatment left Gregor almost invincible, albeit with a dulled mind. He joined the Kingsguard of King Tommen I Baratheon, but primarily served as Cersei Lannister's personal bodyguard. Shortly following Cersei's ascent to the Iron Throne, she named Gregor as Lord Commander of the Queensguard. Gregor continued to faithfully serve Cersei until his death during the Siege of King's Landing, only killed after he was crash-tackled out of the Red Keep onto flaming battlements by his younger brother, Sandor Clegane.