We all knew going into the sixth season of Game of Thrones that Robert Strong—a large and helmeted knight—was really the resurrected Ser Gregor Clegane, who had perished following the gruesome battle with Oberyn Martell. But what we didn’t know is what he would look like.
Source: io9 – Get A Closer Look At This Game of Thrones Knightmare–I Mean Robert Strong