"According to these scraps of information, 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. They were only partly material - as we understand matter - and their type of consciousness and media of perception differed widely from those of terrestrial organisms. For example, their senses did not include that of sight; their mental world being a strange, non-visual pattern of impressions.
They were, however, sufficiently material to use implements of normal matter when in cosmic areas containing it; and they required housing - albeit of a peculiar kind. Though their senses could penetrate all material barriers, their substance could not; and certain forms of electrical energy could wholly destroy them. They had the power of aërial motion, despite the absence of wings or any other visible means of levitation. Their minds were of such texture that no exchange with them could be effected by the Great Race.
When these things had come to the earth they had built mighty basalt cities of windowless towers, and had preyed horribly upon the beings they found. Thus it was when the minds of the Great Race sped across the void from that obscure, trans-galactic world known in the disturbing and debatable Eltdown Shards as Yith.
The newcomers, with the instruments they created, had found it easy to subdue the predatory entities and drive them down to those caverns of inner earth which they had already joined to their abodes and begun to inhabit. ... There were veiled suggestions of a monstrous plasticity, and of temporary lapses of visibility, while other fragmentary whispers referred to their control and military use of great winds. 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'

This is my depiction of the war between the Great Race of Yith and their horrific enemies, the Flying Polyps.