Adding grass to the terrain and Hair and Fur adjustments:
It is the image I used for the background.
It had so cold colors and I would like to have a warmer background so I used Photoshop and Levels to change the colors, also I added a warm gradient color under clouds near the horizon. Color changes done and included the Eagle.
Now I have done the Final Rendering. I used Light Room and Photoshop for final touches, I changed the brightness, contrast and colors in some parts of the image and here is the final image.