The Mountain's distinctive and deteriorating appearance in Game of Thrones was a direct consequence of a severe poisoning he suffered during his trial by combat.
During his duel with Oberyn Martell, Gregor Clegane, known as The Mountain, was gravely injured. It was later revealed that Oberyn had laced his weapon with manticore venom, a potent and insidious poison. This venom did not kill The Mountain immediately but instead condemned him to a slow, agonizing death.
The Impact of Manticore Venom
The manticore venom caused a gradual and excruciating physical decline. As the poison worked its way through his system, The Mountain's body began to fail, leading to:
- Intense suffering: He was in constant, agonizing pain.
- Physical deterioration: His condition worsened progressively, making him appear increasingly disfigured and unhealthy.
- Slow demise: The venom was designed to prolong his suffering, causing a drawn-out and painful end.
This deteriorating state necessitated extreme measures. To prevent his death and potentially create a formidable new weapon, Qyburn, the disgraced Maester, took charge of Gregor Clegane's treatment. Qyburn's experimental and dark arts transformed The Mountain, resulting in his eventual appearance as the silent, undead Ser Robert Strong, serving as Cersei Lannister's personal guard. His altered appearance, including his size, pallor, and often hidden face, was a direct result of both the poisoning that nearly killed him and Qyburn's subsequent, radical procedures to revive and reanimate him.
