The photo shows a fallow deer crossing a ride through oak woods, shortly after dawn. Below are some more photographs from the day and a short explanation of how I made the image.
Below left is the photograph as it came out of camera (shot in RAW format), and below right is the edited image - click on them to see them larger. As you can see, the edited image is not that different from the actual scene, although I cropped out part of the trees on the right as it seemed to make the image more balanced. You may have spotted that there were actually two deer in the scene! Two the right of 'the' deer is another one, with only its body showing above the horizon line, which I edited out of the final image.
At the same time, I would not have taken the photograph with no deer present, and then added in the silhouette of a deer taken at a different time or place. While that would be not that difficult to do, it would seem dishonest to me, or at least would mean creating an image that should be filed under 'art' rather than 'wildlife photography'.