The Yellow King is one of the cyclopean entities known as the Great Old Ones. His religious symbol is a three-sided, tentacled device known as the "Yellow Sign". Carcosa seeks to constantly consume other cities and grow in size, and when it grows big enough it will burst, turning Hastur from a Great Old One into an Outer God. Those who read The King in Yellow expose themselves to its influence, and when the play is performed, the city that hosts it will be absorbed by Carcosa.