Dark Unicorn

Detail link: https://www.renderosity.com/marketplace/products/90295
Requirements: Any software that will open jpg files.
Dark Unicorn is a collection of 10 fantasy backgrounds featuring unusual, elegant, dark unicorns perfect for your fantasy renders. Created with attention to detail, with hand painting, 3D rendering and photographs, they are of highest quality to ensure you get excellent product.
Licensed for commercial and personal use.
Size of each is 2400x3000px at 300dpi.

Usage tips/limitations:

Commercial and non-commercial use allowed under following conditions:
You may not create new background sets out of these files.
You may not offer them for free or for purchase in a whole or individually.
They have to be incorporated in your artwork without a possibility to extract them (this means you can't offer layered versions of your works created with these images).