So, of course, I had to track that story down. Way to give a specific title to a work, Ted!
I don’t want to give away too many spoilers. To an 80-year-old story :P But I will because the last line of the story just took the story to a different level.
The titular It really is an ur-example of beings like the Heap or the original versions of the Swamp Thing or the Man-Thing. Basically an undead monster with swamp plants over a human skeleton. (Yes, I know Alan Moore ditched that idea to beautiful effect but the Swamp Thing started out that way)
Not that that is spelled out in detail. No, the true nature of It is slowly revealed over the course of the story. It is a mystery to us and everyone in the story, including It itself.
And one of the things that makes Theodore Sturgeon’s work sparkle is the sections written from the It’s point of view. It is not a mindless monster but a will that is driven by insatiable curiosity, flawed logic and absolutely no moral compass. Sturgeon succesfully created an inhuman but comprehensible point of view.
But, as i mentioned earlier, what really sold the story for me, what really gave it that punch, was the very last sentence in the story. “And Babe screams at night and has grown very thin” With that direct little sentence and with no details, Sturgeon sold me on the lasting trauma and horror of It.