Great Race of Yith

The Great Race of Yith are aliens in the Cthulhu Mythos of H. P. Lovecraft. They first appeared in Lovecraft's short story "The Shadow Out of Time" (1936). They are called the Great Race because they are the only beings to have mastered time travel. Throughout "The Shadow Out of Time" they are simply referred to as "The Great Race" whilst their planet's name is only mentioned once.