Ghatanothoa is the central mythical deity of Howard Lovecraft's Out of Time, left on Earth by the aliens of Mi-go from the planet Yuggot, long before human civilization began.

Gatanoa is immortal and dwells in a dungeon fortress once located on Mount Yaddith-Gho, in the kingdom of K'naa, on the vanished continent of Mu. Geographically the mountain is located near New Zealand.

To avoid Gatanoa's awakening, the people of the K'naa kingdom sacrificed twelve young warriors and twelve girls every year. Their bodies were burned on bonfires in a marble temple at the foot of the mountain, as no man dared go up to the fortress at the top of the mountain.