Ser Gregor Clegane is the head of House Clegane, a knightly house from the Westerlands, and the elder brother of Sandor Clegane. When Sandor and Gregor were children, Gregor held his brother's face in a fire for playing with one of his toys without permission, horrifically scarring him. Gregor is a landed knight rather than a full-fledged lord. Gregor is monstrously huge, said to be the largest man in Westeros. He is feared throughout Westeros with a reputation for ferocity and anger. He is a loyal retainer and servant of House Lannister, particularly to Lord Tywin. Numerous servants have gone missing at the Clegane keep over the years, apparently killed by Gregor for minor slights in one of his infamous fits of rage, and their deaths then covered up. Gregor's own father and sister died under dubious circumstances as well, and Sandor thinks that Gregor may have killed them as well. Their sister died when Sandor was too young t...