Great Race of Yith

The Great Race of Yith—also known as Yithians—are a race that swap minds with other races throughout time and space in an effort to learn everything they can about the universe. The most famous of their inhabited forms are the conical beings of Earth's prehistoric past. The swapped mind subsequently inhabits the Yithian's body until they return, jotting down all they know of the home for the Yithians' great libraries.

Scions of Tsathoggua

The Scions of Tsathoggua are enormous, bloated, toad-like things. They produce a child-like tittering that has earned them the alternative monicker, The Children of Tsathoggua. They act as the agents and guardians of their sire, Tsathoggua, at its various temples. 

Spawn of Ithaqua

The Spawn of Ithaqua (previously Spawn of the Winds) are half-breed offspring of Ithaqua and a human. They usually appear human, but can transform into creatures more akin to their father.