"The Thing at the Bottom of the Well" is a short-story included in the 1960 self-published magazine People, Places and Things.
The story concerns a small boy who enjoys torturing animals: he tears out the wings of flies, kills worms, or maltreats a dog with needles. One day, he is lured to a well by a strange voice and climbs down, mesmerized. When his body is found, his arms are severed from his body and his eyes are punctured with needles.
Readers of the novel "IT" will find a certain level of familiarity with this story, as it seems to be somewhat of an early precursor to the novel, much in the same way that "Night Surf" seems a precursor to "The Stand".