John Stahl (born 1953 in Sauchie, Clackmannanshire, Scotland) is a Scottish actor, arguably best-known for playing the recurring character of Quinn on the second season of Being Human.
In Game of Thrones he is playing the role of Rickard Karstark, starting in the second season. He replaces Steven Blount, who was announced in the role, but was not identified by name on screen. George R.R. Martin confirmed him in the role on 13 October 2011[1].