Game of Thrones Season 6 Episode 05 The Door
While Meera escapes carrying Bran, Hodor is presumably killed by the wights. In the vision, Bran becomes overwhelmed by the split consciousness and unintentionally wargs into the young Hodor (then named Wylis), forging a connection between the past and present and forcing Wylis to witness his own death, causing him to suffer a seizure. With Bran’s consciousness inside his head, Wylis hears the echoes of Meera’s orders, and begins to slur the words “hold the door” over and over again until “Hodor” is all that he can say.
HODOR: Hold the door! Hold the door! Hold the door! Hold the door! Hold the door! Hold door! Hold door! Hold the door! Hold the door! Hold door! Hold door! Hold door! Hodor! Hodor! Hodor! Hodor! Hodor! Hodor!
Source text: Wikipedia.