Daoloth

"Not shapeless, but so complex that the eye could recognize no describable shape. There were hemispheres and shining metal, coupled by long plastic rods. The rods were of a flat gray color, so that he could not make out which were nearer; they merged into a flat mass from which protruded individual cylinders. As he looked at it, he had a curious feeling that eyes gleamed from between these rods; but wherever he glanced at the construction, he saw only the spaces between them." -- Ramsey Campbell, The Render of the Veils

Daoloth dwells in dimensions beyond the three we know, and his astrologer-priests are said to see the past and future and even how objects extend to and travel between different dimensions.