”The Coming of the White Worm” by Clark Ashton Smith

"The Coming of the White Worm" is a short story by Clark Ashton Smith that takes place in the fictional prehistoric setting of Hyperborea. The tale, which was first published in the April 1941 issue of Stirring Science Stories, and sometimes includes the subtitle, "Chapter IX of the Book of Eibon", concerns the victim of a monstrous entity’s scourge, and his quest to unravel the secret of the beast.