When asked in depth about the show adding the "Night King"(opposed to the books Night's King) GrrM had this to say: As for the Night's King (the form I prefer), in the books he is a legendary figure, akin to Lann the Clever and Brandon the Builder, and no more likely to have survived >to the present day than they have. You have the book character, the Night's King, which was the 13th Lord Commander of the Night's Watch who wed himself to a female other and started to make changes to the Night's Watch and using dark magics. He was defeated by an alliance between the current Stark King. The Night King is a creation for the show to be a leader of the Others and The actor who plays the Night King on Game of Thrones just explained why he didn’t fight Jon Snow during the Battle of Winterfell. You know, aside from the fact that Jon was preoccupied with the The show showed us the making of the Night King for a reason as the Night King is to be that first man, now we may find out who that man is, they may even mix up book cannon and account for him being the same Night King as mentioned in the book and therefore he could be a Stark, they could make him a Stark anyway but I am not sure but whoever Night Shift is the first book for which King wrote a foreword. The introduction was written by one of King's favorite authors, John D. MacDonald . MacDonald writes that "Stephen King is a far, far better writer at thirty than I was at thirty, or at forty. (For the curious, the Night’s King of the books is the legendary 13th Lord Commander of the Night’s Watch. He fell in love with a mysterious, white-skinned, blue-eyed, ice-cold woman, declared Additionally, the Night King chooses not to go after Jon, at least not directly, in the season 7 episode "Beyond the Wall." Instead, he shoots down Daenerys Targaryen's dragon Viserion. One of those big moments in the Godswood is, of course, the moment that Bran gave Arya the dagger she would use to kill the Night King himself. This dagger comes with a long history - having originally appeared in season 1, when it was used to try and kill Bran. Having it finally used to kill the Night King and protect Bran is a beautiful way .

is the night king in the books