Great Intelligence

Yog-Sothoth was a Great Old One. According to some accounts, it was another name for the Great Intelligence. (PROSE: Millennial Rites, Legacies)

According to one source, Rassilon gave Yog-Sothoth its name in this universe. (PROSE: Divided Loyalties)

According to another account, Yog-Sothoth was a member, and the military strategist, of the Great Old Ones, who were the equivalent of the Time Lords in a previous universe to the one the Doctor resided. They shunted themselves into a parallel universe to pass into the next universe. Yog-Sothoth discovered it had gained god-like powers and decided to try the various gambits and games it had only played on computers.

Over the billennia, it mounted millions of campaigns against inhabited planets. It used the Hisk version of koalas on Hiskith and domestic animals equivalent to dogs on Danos. Yog-Sothoth was temporarily trapped in the Great Kingdom when the Kingdom was brought into existence by the Millennium Codex in 1999. (PROSE: Millennial Rites)

Behind the scenes

 * Yog-Sothoth is the name of a fictional deity created by H. P. Lovecraft, first appearing in . It was implied to be one of the most powerful beings in the universe (second to only Azathoth), the key and the gate through which the Old Ones entered the world. Its appearance is often a mass of iridescent spheres and is described as being imprisoned outside of the space-time continuum in a place where it exists at every point in time and space.