"A Tropical Horror" is a short story by William Hope Hodgson, first published in 1905.
The story is told from the point of view of the sole survivor, a young apprentice.
The creature is aboard the ship for several days and gradually kills and/or eats the remainder of the crew.
The end of the story is presented using a literary device in the form of a report from another ship, which has rescued the sole survivor.
They validate his story, finding the ship damaged and the crew missing or dead.