Premise: Game of Thrones . The series premiered on HBO in the United States on April 17 , 2011 , and its sixth season ended on June 26 , 2016 . Ser Gregor Clegane , nicknamed The Mountain , is a fictional character in the A Song of Ice and Fire series of fantasy novels by American author George R. R. Martin , and its television adaptation Game of Thrones . Introduced in 1996 's A Game of Thrones , Gregor is the older brother of Sandor Clegane , from the fictional kingdom of Westeros .
Hypothesis: Gregor Clegane is a character from the HBO series Game of Thrones.
Label: ENTAILMENT