The term "Old Ones" is a reference to ancient and powerful beings in H.P Lovecraft's Cthulhu Mythos, which is a shared universe of fictional stories centered around the mythology of author H. P. Lovecraft. These beings are described as being humanoid or non-human entities that existed since before human history began and possess immense power and knowledge beyond human understanding. They are often associated with cosmic horrors, ancient gods, and other supernatural forces.