Flying Polyp is a fictional species which appears in H.P. Lovecraft's novel The Shadow out of Time. In the story, they came to Earth out of space as conquerors about seven hundred and fifty million years ago. They build basalt cities with high windowless towers and inhabited three other planets in the solar system. On Earth, they were warred and finally forced underground by the Great Race of Yith, but near the close of the Cretaceous era (about 50 million years ago) they rose up from their subterranean haunts and exterminated the Great Race.

The polyps still remain in their caverns and seem content to remain there, annihilating the few beings chancing across them. The entrances to their dwellings are mostly deep within ancient ruins where there are great wells sealed over with stone. Inside these wells dwell the polyps still.

"A horrible elder race of half polypous, utterly alien entities... They were only partly material and had the power of aerial motion, despite the absence of wings... Suggestions of a monstrous plasticity and of temporary lapses of visibility... singular whistling noises and colossal footprints made up of five circular toe marks seemed also to be associated with them." - H.P. Lovecraft, The Shadow Out of Time.