Making the Monster
Sunken eyes, disproportionate body parts, contrasting hair, and pale colored skin. These are the things that generally freak people out the most when applied to a humanoid figure. What we'll start out by doing is de-saturating the picture almost all the way to being completely gray scale, but add a hue to make a paler, unnatural looking skin. This is all done in the 'Hue/Saturation' window which is located the 'Image > Adjustments' tab. This is the result of that with the values I used off to the right.
Now we will make the hair a bit darker, so we'll use the Masking Tool to get our selection again, but this time it has to be inverted. This can be done by going to the 'Selection' tab at the top of your Photoshop window and selecting the 'Inverse' option, to select the hair. Using the 'Brightness/Contrast' window which is also located under 'Image > Adjustments' we will alter the values to achieve darker hair.
The eyes will likely be the most important thing we change about this picture. So we'll start out by editing the base of the eyes and making them look more sunken by using the Burn Tool around the eye.
Then we'll remove the iris and pupils by just going in with a soft brush with a color picked from the cornea of the eye to give it a really paranormal vibe.
You can add whatever extra touches you'd like but for all intents purposes this is pretty good where we are. Save your picture just in case and we'll move to place him in his natural habitat.