Howland Reed's younger child, Jojen is barely an adolescent when he arrives at Winterfell, but his gravity and mature personality make him seem older. He has unusually deep green eyes and wears green clothing. Jojen has greensight, the power of prophetic dreams. When Jojen is introduced into the story, his powers of prophesy impress Bran Stark. However Jojen surprises Bran by saying that Bran's powers are far stronger than his own, but he is not trained to use them. Therefore, Jojen creates a number of activities for Bran to develop his powers. Bran resists this, but Jojen continues to encourage him.

When Bran tells Jojen of his own prophetic dream about the "Three Eyed Crow" when he was in a coma, Jojen starts pushing Bran to travel north of the Wall to find out more about his dream. While Theon sacked Winterfell, Jojen, Meera, Bran, Hodor, Rickon, and Osha hid in the castle's tombs. After the violence had ended, the group split and Jojen, Meera, Bran and Hodor fled north. At the very end of A Storm of Swords, they pass through a secret gate under the Wall (with Samwell Tarly's help), in search of The Three Eyed Crow and a mysterious entity known as Coldhands.

From "A Song of Ice and Fire" by George R R Martin