"I saw Bran's wolf tear out a man's throat at Winterfell, and loved him for it."
Catelyn regarding Summer.

Summer is the direwolf bonded to Bran Stark. Born with five other siblings, Summer has silvery grey fur and yellow eyes. Summer saved Bran's life by killing his would-be assassin, and later followed Bran when he left Winterfell. Summer ventured with him beyond the Wall, and reached the three-eyed crow's cave. In the show, Summer is later killed by a horde of wights when the White Walkers attack the cave. In the books, Summer is present when Bran wakes up following a wight raid, and manages to take command of a pack of wolves after killing their alpha, One Eye.