Great Old Ones (Doctor Who)

The Great Old Ones were formerly the most powerful beings in the universe prior to this one- the Time Lords of their reality, they were all masters of the dark science known as quantum mnemonics. Seeking to evade the death of their universe, they shunted themselves into a parallel dimension which collapsed a few seconds after their own, then transferred to the newly born universe just after Event One. They found that the laws of physics in the new universe led to them gaining god-like powers, and they decided to act as gods thereafter.

The Great Old Ones, as they came to be called, spread across the universe, exercising their might through chaos and conquest, becoming objects of worship for countless primal races. Yog-Sothoth, later known as the Great Intelligence, played out military campaigns it had only dreamed of in the old reality. Lloigor, later known as the Animus, conquered Vortis. Hastur, who became known as Fenric, and Nyarlathotep went their own ways, while Shub-Niggurath conquered Polymos and populated it with its offspring, the Nestene Consciousness. Other Old Ones included Cthulu, Dagon and the Gods of Ragnarok.

Some of the Old Ones, such as Cthulu, slumber until the time when the stars are right, while others roam the universe spreading terror.