The Worm that Gnaws in the Night

The Worm that Gnaws in the Night (the Doom of Shaggai) is an entity that appears in Lin Carter's short story "Shaggai" (1971). The being is portrayed as an enormous, worm-like entity. The Worm was first observed by the Eibon, who chanced upon it on a sojourn to the planet Shaggai. To his horror, Eibon discovered that the massive worm was slowly eating away at the vitals of Shaggai and subsequently made a hasty return to Earth.

It appears to be similar in size and description to the Graboids from the popular movie series Tremors.