Hodor

Although the Stark children always believed Hodor was his real name, Old Nan—his great-grandmother and the only kin he has left—insists his true name is Walder. No one remembers where the word he keeps repeating came from; one day he simply started saying it, and everyone else began calling him that.

Walder's family has thinned out with every war the realm has fought. Old Nan's two sons, including the boy's own grandfather, died during Robert's Rebellion, and his father later fell at the siege of Pyke, during the Greyjoy uprising. Of that line, only he remains.

As a child, on a trip to the market square in Winterfell with Lady Catelyn and Septa Mordane, he wandered off and was found in an alley being beaten with sticks by other boys, never once raising a hand to defend himself. Even then he was enormously tall, brown-eyed and brown-bearded, standing well over seven feet, with a temperament as gentle as his body was huge; some say a size like that can only come from giant's blood.

After Bran's fall, Maester Luwin designs a basket that can be strapped to Hodor's back so the boy can ride inside it. From then on, Hodor becomes Bran's way of getting around; being slow-witted, he sometimes forgets he's carrying someone, and Bran ends up bruised more than once because of it.

When the North answers Robb's call after Lord Eddard's arrest, Bran asks to be taken to Winterfell's godswood. While the boy enjoys the quiet of the place, Hodor strips and sinks into the hottest pool; seeing him, Osha remarks that only giant's blood could explain a size like that.

The crypts, though, are another matter — Hodor refuses to go down into them, and it falls to Osha to carry Bran that time.

When Theon Greyjoy seizes Winterfell, Hodor takes shelter in the crypts with Osha, Bran, Rickon, and the Reed siblings, Meera and Jojen, letting everyone believe they had fled the castle. Food runs low and the group eventually has to come back up, where they find the castle in ruins.

Before leaving the crypts, each of them takes a sword from among the Stark tombs; the one that falls to Hodor is an old, heavy piece of iron, dulled by centuries of neglect and pitted with rust.

After speaking with a dying Maester Luwin, they decide to split the two brothers up: Rickon stays with Osha, while Hodor sets out with Bran, Jojen, and Meera toward the Wall.

The group continues north and reaches Queenscrown, where they spend the night. There they spot Jon Snow from a distance, travelling with a band of wildlings led by Styr; Bran, warged into Summer, attacks the wildlings and lets Jon get away.

Further on they reach the Nightfort, right by the Wall, where they run into Samwell Tarly of the Night's Watch. Sam leads them through a hidden door at the bottom of a well and down a tunnel that runs beneath the ice to the other side.

Once north of the Wall, they cross paths with Coldhands, a strange creature whose loyalties are impossible to pin down.

After a long march, the group reaches the cave of the three-eyed raven. Wights ambush them right at the entrance; Bran slips into Hodor's mind to fight them off, but blacks out and wakes up already inside, safe among the last of the Children of the Forest and the raven itself.

Inside the cave, Bran keeps entering Hodor's mind whenever he wants to explore its deepest corners. Hodor slowly gets used to that shared presence, though the fear never quite goes away — there's a part of himself Bran can never reach, a place Hodor withdraws to when it all becomes too much.

From this point on, Hodor's story splits in two depending on the medium. In the novels published so far, it remains open: he's still alive, sharing his mind with Bran somewhere inside that cave.

The television series, on the other hand, gives him a definite ending, treating Hodor as dead by the year 303 AC — though the material behind this entry doesn't cover how that comes about.