The term "Great Old One" refers to a category of ancient, powerful entities in the fictional universe created by writer H.P. Lovecraft. These beings are often depicted as cosmic horrors that exist beyond human comprehension, embodying chaos and madness. They are typically associated with themes of existential dread and the insignificance of humanity in the vast universe. In Lovecraft's works, the Great Old Ones are often worshipped by cults and are linked to forbidden knowledge. Notable examples include Cthulhu, a monstrous entity that lies dormant beneath the sea, and Yog-Sothoth, who exists outside of time and space. Their influence often leads to catastrophic events in the stories.