Qyburn

Qyburn is a character in the third season. He is portrayed by Anton Lesser and debuts in "Valar Dohaeris". He wears the maester chain and is part of the Northern forces in the War of the Five Kings.

Season 3
Qyburn is among the Northern and Riverlands prisoners at Harrenhal when Ser Gregor Clegane abandons the castle and has all captives put to the sword. Qyburn, however, survives the injury at his throat and awakens when the castle is taken by the Northern army. After he wakes, he identifies himself to Robb Stark while Talisa Maegyr tends to his wound.

In the books
In the A Song of Ice and Fire novels, Qyburn is a former maester who acts as a healer in the sellsword company known as the Brave Companions. While highly skilled in medicine and knowledge of the human body, he was stripped of his title and expelled from the order of maesters when it was discovered that he was conducting unethical medical experiments on living people. While for centuries the maesters have dissected the bodies of the dead to gain knowledge of the living, Qyburn opened up the bodies of the still living to try to gain knowledge about the processes of death. Qyburn's experiments killed many innocent people, but are rumored to have given him advanced, unnatural medical knowledge.

Ironically, given Qyburn's unethical mindset and willingness to conduct warped medical experiments on the living, Qyburn is described as looking like some little girl's favorite grandfather. Qyburn is an old man with gray hair, and crinkles around his warm, fatherly eyes.