Is Rust the Yellow King?

Rust Cohle Is Actually the Yellow King.

What is the Yellow King in True Detective?

Hastur, also known as the Yellow King, is a fictional cosmic entity that first appeared in Ambrose Bierce's short story Haïta the Shepherd (1893) and was later expanded on by Robert W. Chambers, H.P. Lovecraft and August Derleth. He could be considered as the unseen antagonist of Season 1.

Why is he called the Yellow King?

Errol Childress, the Yellow King's true identity, is described by children as the “spaghetti-faced man” owing to his distinctive facial scars. This could be an allusion to Cthulhu himself, the bat-winged behemoth with the head of an octopus and tentacles over his mouth.