Nice idea, but I think you should work a bit more on the blending...

i think if you make the eagles haed look like stone to match .. then play with the perspective i think you will have a verg good entry author !

Masking of the edges needs work -- bottom edge and the left edge are showing straight lines --- a bit of work with the perspective transformation would also help

Definitely make the color match and fix the blending...

don't know why but something just doesn't look right.... match the color, use a harder brush when masking (cause we're dealing with rock here, right?) then we'll have something

You should have just turned the eagle face to stone. Too late now I know.

Pitty you did not get time to play with the bird texture. The source does not sit well with the image you have chosen. you may like to explore tutorials that cover overlaying textures. GL