- "...the basis of the fear was a horrible elder race of half-polypous, utterly alien entities which had come through space from immeasurably distant universes and had dominated the earth and three other solar planets about 600 million years ago."
- -H.P. Lovecraft, The Shadow Out Of Time
The precise nature of the flying polyps is unclear; the records kept by the Great Race of Yith are notably evasive, making fearful references but shying away from actual description. They are capable of flight, although they lack wings or other appendages to facilitate this, and they were capable of controlling air currents for offensive and manipulation purposes. Although airborne, they seem to make some contact with the ground during movement, as they leave behind five-toed radial footprints wherever they go.
The flying polyps first colonized the Earth about six hundred million years ago, predating the arrival of the Great Race of Yith. They built vast cities of basalt, their defining architectural features being tall windowless pillars or towers. They were an aggressive and predatory species, and when the Great Race transferred their minds to the indigenous organisms that would harbor them for aeons to come, they came into conflict with the polyps. The Great Race prevailed at first due to their superior technology, forcing the polyps back to the subterranean catacombs that lay beneath their cities and sealing off the tunnels with reinforced trap-doors.