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when do you see white walkers in game of thrones
White Walkers appear at the beginning of the first episode of Game of Thrones, Winter Is Coming.
who is the leader of the white walkers in game of thrones
The Night King is the leader of the White Walkers in the television series Game of Thrones.

Question: who plays the king
Self-contained rewrite: who plays the night king, leader of the white walkers, in game of thrones