Popular for playing the role of the monster Demogorgon in Stranger Things in 2016-2017, Mark Steger is an American actor, performance artist, and choreographer, who is known for his creature roles in Hollywood. Towards the beginning of his career, Steger featured in the music videos of the heavy metal band Metallica. He was then cast in I Am Legend (2007), Mr. Jones (2013), World War Z (2013), Paranormal Activity: The Ghost Dimension (2015) before he joined the cast of The Nun (2018).