"During that first winter he produced five of his best-known short stories—“The Burrower Beneath”, “The Stairs in the Crypt”, “Shaggai”, “In the Vale of Pnath”, and “The Feaster From the Stars”—and painted seven canvases; studies of nameless, unhuman monsters, and profoundly alien, non-terrestrial landscapes."
H.P. Lovecraft, The Haunter Of the Dark
"And might I further tell you what you saw on those unknown tunnel walls; that those oddly dimensioned designs depicted living creatures of sorts-like elongated octopuses or squids but without recognizable heads or eyes-tentacled worms in fact but of gigantic size?"
"To make it short, Henri, I have been dreaming of subterranean beings, octopus-things apparently without heads or eyes, creatures capable of organic tunneling through the deepest buried rocks with as little effort as hot knives slicing butter! I don't know for sure yet just what they are, these burrowers beneath; "
For Ellis' mind was with Shudde-M'ell when in blind agony and indescribable rage, the Prime Burrower broke through the crust of the Earth-broke through to swim away deeper yet, into the inner magma, against strange tides of molten-rock oceans, those oceans which hold these lily pads we call continents afloat!"
"And Shudde-M'ell-what of the Prime Burrower now?"
It was octopoid, this dweller in the earth...flowing tentacles and pulpy gray-black, elongated sack of a body...rubbery...exuding a vilely stinking whitish slime... eyeless...headless too...Indeed I could see no distinguishing features at all other than the reaching, groping tentacles. Or was there-yes!-a lump in the upper body of the thing....a container of sorts for the brain, or ganglia or whichever diseased organ governed this horror's loathsome life!
Brian Lumley, The Burrowers Beneath