Wikipedia calls this one of the influences on H P Lovecraft's "Dagon", the first Lovecraft story that introduces an element of famous Cthulhu Mythos.
Having read both stories, I personally don't see a connection (but there is an episode similar to this in Lovecraft's "The Call of the Cthulhu"). Both involve water monsters, but there is no dearth of stories of that. This story features a man who's speculated to be part fish - but a man who's son of a man & a woman, nevertheless! "Dagon" features intelligent people who live at the ocean bottom.
Story summary."Fishhead", "a human monstrosity", son "of a negro father and a half-breed Indian mother", is a loner & lives at the banks of the huge "Reelfoot Lake". He knows the lake & its ecology like no other man.
Brothers Jake & Joel Baxter, "poor whites", picked a feud with him over nothing, slapped him, & got "the beating of their lives".
"two freeborn, sovereign whites -- to be licked by a nigger!" So they're going to kill Fishhead. They will succeed, but will, in turn, get justice at the hands of lake animals that Fishhead was friends with.
Fact sheet.First published: The Cavalier, 11 January 1913.
Download full text from Gaslight.
Related: Fiction from 1910s.