I don't know if this qualifies, since it was commercially released. But then again that was almost a hundred years ago... Dagon
from H.P. Lovecraft, one of the first stories he wrote and a very good one I think.
I think (correct me if I'm wrong) that Lovercraft universe is currently public domain as enough time passed since his death?
If that's true - this entry is valid ; )
That was my thinking. :-)
As it was published before 1923 it is also a very clear case. For works that were published at a later date this seems much more complicated according to wikipedia.