In George R.R. Martin's books, Bran Stark is helped to the cave of the Three-Eyed Raven by a mysterious figure we know as Coldhands. The character has the look of a wight and has blackened hands from congealed blood. We don't know much about Coldhands' past except that his clothes make it appear that he was a member of the Night's Watch.
Though the character's true identity is a mystery, fans have theorized for a while that Coldhands is secretly Benjen Stark, Bran's uncle who went missing after going beyond the Wall.