Original Photo (Came from Photoshop Talent) so it must be copyright free, Right?
step 2 of 4
I selected parts of the shell and moved them into the shape of the seal head.
step 3 of 4
Added some shadow for depth.
step 4 of 4
Final image, I added a tounge, worked on the edge of the mouth. the inner part of the mouth is the original photo coming through for the inside of the mouth. also I did some clone stamp tool and some masking for the sand. I made the eye and the tounge (photoshopped) I used a bit of dodge and burn tool brush for some contrast too.