In September 1930 there was a disastrous expedition to Antarctica by explorers led by Dr William Dyer of Miskatonic University. The scientists encountered a shoggoth, a species of slave race created by the Elder Things and narrowly escape (At the Mountains of Madness HP Lovecraft)
•    The Elder Things (also Old Ones and Elder Ones) are extraterrestrials who came to earth and colonized it about one billion years ago. They also created the Shoggoths a slave race. They warred with the star spawn of Cthulhu and the Great Race of Yith and the Mi-go, but died out during the last ice age.(HPLovecraft)
•    Shoggoths, protoplasmic creatures created as a slave race by the Elder things but who rebelled. Some still exist in remote parts of the earth (HPLovecraft)
•    Cthulhu a Great Old One hibernates in R’lyeh, an underwater city in the South Pacific (HPLovecraft). His presence is sensed on a deep level by humanity and there are cults to him around the world
•    The Great Old Ones are a loose pantheon of ancient, powerful deities from space who once ruled Earth and have since fallen into a deathlike sleep (HPLovecraft)
•    The Great Race of Yith was a prehistoric civilization on earth (from the dying planet of Yith) until their demis in the late Cretaceous era. They mastered precognition through time travel into other creatures minds (HPLovecraft)
•    Mi-Go are ancient fungoid extraterrestrials are hunted by the Brotherhood of the Yellow Sign in the 1930s (HPLovecraft)
•    The Necronomicon is a grimoire of supernatural history, specifically pertaining to the Great Old Ones that has appeared in various times throughout history. (HPLovecraft)