Enchanting Journey: A Ghibli Style Fantasy Book Cover

You are making a book cover with the art style similar to studio ghibli with similarities to princess mononoke movie style. The title is called "The River Forest" and the author name is Mara Parrish. The cover should have a dark forest with a deep, deep river snaking through it. Birds eye view. In the river is a gigantic beast made of shadows, much like a water dragon but made of shadows. There is massive bones in the water to indicate how dangerous it is. the overall vibe of the cover should be dark and eerie, spiritual, magical.