Tion Frey

Third son of Ser Emmon Frey and Genna Lannister, born at Casterly Rock and squired for the westermen by virtue of his Lannister blood. He rode with his cousin Ser Jaime Lannister at the Whispering Wood and was taken alive there beside Jaime and his cousin Willem Lannister, then held at Riverrun while Robb Stark and Tyrion Lannister haggled fruitlessly over his exchange for Arya and Sansa. After Catelyn Stark loosed the Kingslayer in secret, Lord Rickard Karstark, robbed of his vengeance for Torrhen and Eddard, slipped into the cells with ten of his men and butchered the two Lannister boys in their straw; Tion, brown-haired and waking, fought for his life and died of it, and Robb struck off Lord Rickard's head for the deed.