Yog-Sothoth

Yog-Sothoth was a Great Old One whom the Seventh Doctor said he'd "met in Tibet and again in London", (PROSE: All-Consuming Fire) and an alleged real identity of the Great Intelligence. (PROSE: Millennial Rites)

Origins

As a member of an earlier race of Time Lords

According to one account, in his original form, Yog-Sothoth was a member, and the military strategist, of the earlier race of Time Lords who ruled over the universe which existed before the one in which 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.

This account held that Yog-Sothoth was the same entity as that known to the Doctor as the Great Intelligence, (PROSE: Millennial Rites) whom another account confirmed to be a Great Old One. (AUDIO: The Roof of the World)

However, other, contradictory accounts of the Intelligence's nature and origin existed. (PROSE: Doctor Who and the Web of Fear, The Forgotten Son, Legacies, Night of the Intelligence)

As fiction

Yog-Sothoth was one of the fictional characters that Missy had to defeat in order to take over the Land of Fiction. (PROSE: The Wonderful Doctor of Oz)

History

Yog-Sothoth regularly intervened in the modern universe, enacting "billions" of gambits. In at least one of these accounts, Yog-Sothoth was the Great Intelligence. (PROSE: Millennial Rites ^[+]Loading...["Millennial Rites (novel)"], All-Consuming Fire ^[+]Loading...["All-Consuming Fire (novel)"])

It was Yog-Sothoth, "The Key to the Gate", which kept the walls of the universe, beyond which the Outer Void lay, in check. Dionus noted that Yog-Sothoth "wouldn't allow" Gods of other universes into this one. (PROSE: Love & War ^[+]Loading...["Love & War (short story)"])

He desired to "know" the universe; not to invade or conquer it, but to experience it. For this reason, he "shattered" himself into small, unmeltable fragments of snow. Consequently, he had seen and known all, and he had wept for the tragedy. Due to a certain Archon breaking a whole in Urizen's Wall - quite possibly by accident - Yog-Sothoth entered the Library of the Plume Coteries by becoming the Snowstorm with the intention to read every book. (PROSE: The Book of the Snowstorm ^[+]Loading...["The Book of the Snowstorm (short story)"])

Behind the scenes

• Yog-Sothoth is one of the Great Old Ones from H. P. Lovecraft's public-domain Cthulhu Mythos, which All-Consuming Fire brought into the fold of the Doctor Who universe. Second only in power to Azathoth among the Great Old Ones, Lovecraft's Yog-Sothoth often appeared as a mass of spheres.
• Although only Millennial Rites was able to confirm this link, the implication that Yog-Sothoth and the Great Intelligence were one was already present in All-Consuming Fire, due to the locations in which the Doctor says he battled Yog-Sothoth. However, from a legal standpoint, it does not appear that the Great Intelligence can be said to feature in All-Consuming Fire, which features no copyright credit to the Intelligence's creators Mervyn Haisman and Henry Lincoln (as indeed it wouldn't have to for mentioning the public-domain Yog-Sothoth and very faintly implying a connection to an old Doctor Who character).