The Horror at Martin’s Beach by H. P. Lovecraft and Sonia Greene

THE HORROR AT MARTIN'S BEACH is a short story by H. P. Lovecraft and Sonia H. Greene, first published in the November 1923 edition of Weird Tales as "The Invisible Monster". The story tells of a horrifying creature killed by sailors at sea, and of the resulting act of vengeance on behalf of the creature’s mother.