Premise: Gregor Clegane . Introduced in 1996 's A Game of Thrones , Gregor is the older brother of Sandor Clegane , from the fictional kingdom of Westeros . He subsequently appeared in Martin 's A Clash of Kings ( 1998 ) , A Storm of Swords ( 2000 ) and in A Dance with Dragons ( 2011 ) as Ser Robert Strong .
Hypothesis: Gregor Clegane is a character.
Label: ENTAILMENT