In the novella
"At the Mountains of Madness
" by H.P. Lovecraft
, a race of alien
beings who, millions of years ago, built a vast civilization
somewhere on the continent of Antarctica
. They were eventually destroyed by their artificially-created servants the Shoggoths
As a race they are distinct from the Great Old Ones, that assortment of extraterrestrial menaces that includes Cthulhu and Yog-Sothoth.