Hammer is a warhorse.
Hammer is a tall, bay gelding. He is powerful, sleek and fast.
Hammer carries Tervail Dura to Tar Valon and the White Tower through a gateway from the Rebel Aes Sedai camp. Both Tervail and Beonin Marinye, riding Winterfinch, were sneaking back to the Tower after Egwene al'Vere had been captured.