Neil Fingleton, the man who brought the Game of Thrones giant Mag the Mighty to life, has passed away from apparent heart failure. He was 36 years old.

Fingleton, who stood 7-feet and 7-inches tall, received the Guinness World Record in 2016 for being named Britain’s Tallest Man. He started out as a basketball player in the United States before switching to acting.

He appeared as the Fisher King on Doctor Who, and did various roles (including stunt work) on films like Marvel’s Age of Ultron, X-Men: First Class, and Jupiter Ascending.

Many Game of Thrones fans remember his portrayal of Mag the Mighty in the season 4 episode, “The Watchers on the Wall.” Mag the Mighty was the giant who forced his way into the tunnel underneath the Wall before he was killed by the Night’s Watch.