Who is the night king in Game of Thrones?

The American TV series Game of Thrones is different from the original book in setting the night king, which is why people are always confused.

In the original book, the Night King is the 13th Commander-in-Chief of the Night Watch, from the Stark family. He fell in love with a woman whose skin is as pale as the moon, her eyes are like blue stars and her skin is as cold as ice. It's a ghost.

He took her back to the Long Night Castle and called her the queen. He also offered sacrifices to other ghosts. Later, it was defeated by Brandon, the king of the Winter Land, and Joe Manchester, the king of the Great Wall.

Note that the Night King here didn't lead the army of aliens and ghouls to attack mankind. He was a human being and lived in the Nightcastle with the self-appointed queen.

The Night King in the American drama Game of Thrones is defined as the chief leader of ghosts and ghouls. As for his origin, people speculated that he was Bran, but it was obviously not confirmed until the end of the play.

In the play, after Bran became a three-eyed crow, he saw the first strange ghost through the green vision. Guide the audience to think that the first alien ghost is the later night king, who can transform the baby into an alien ghost, and raise his hand to make the dead have the ability to act.