The center, bird-like creature reminds of something out of the work of graphic novelist Jason. I see someone else here, too, but can't quite recall. Regardless it, again, is singularly the work of one Matt Kish. The expansive details never fail to impress.
I am certain Jason is an influence as I enjoy his work, especially his wordless comics, immensely. But as you surmised, most of these images are the result of the melange of images that have been stewing in my head for decades. I am very fond of this particular piece, but it did take a ghastly amount of time to complete.