Walder Frey, called Big Walder, is a eight-years-old grandson of Lord Walder Frey. He quarters his arms with the arms of his mother, a Paege, and his grandmother, a Blackwood.
He was sent to Winterfell as a ward of Lady Catelyn as part of her negotiations with Lord Walder Frey. After the razing of Winterfell at the command of Ramsay Snow, the Bastard of Bolton, the Walders were taken by Ramsay to the Dreadfort.