- "Gods aren't down here. It's the six of us, you hear me!?"
- ―Grenn to Cooper.
Grenn is a ranger in the Night's Watch, and a convicted criminal in the Seven Kingdoms of Westeros. Strong but dim-witted, Grenn was caught committing a crime somewhere in the Kingdoms, Grenn was given a choice of losing a hand or the Wall: Grenn chose to take the black. He was trained at Castle Black by Ser Alliser Thorne, where he eventually became a close friend of Jon Snow. Grenn takes part in the Great Ranging, where he is one of the few survivors of a massive White Walker assault at the Fist of the First Men. Later, at Craster's Keep, he fought on Mormont's side during the mutiny, and managed to survive and escape to Castle Black. In the show, Grenn takes part in the raid to kill the mutineers, and later dies holding the gate against a giant during the Battle of Castle Black. In the books, Grenn survives the Battle of Castle Black, and when Jon Snow becomes Lord Commander, is assigned to Eastwatch-by-the-Sea.