The first you open an image below:
Create a new layer and fill it with #B9B0AD. Set it to Color Burn, opacity 100%.
Use this texture, put it above the image as shown below (Press Ctrl+T to rotate it).
Set the texture to Color Burn, opacity 80%.
Add mask layer to the texture, use this brush to erase some areas as shown below:
Open "Snake" image:
Use pen tool (P) to make a selection around the snake.
Drag the snake to your work. Go to Edit -> Transform -> Flip Horizontal.
Add mask layer to the snake, use brush to erase the part of snake's body in man's neck (You can also use Eraser tool (E) to erase).
Now press Ctrl+M and set curve as the picture below to make the snake darker.
Go to Layer -> Layer style -> Drop shadow, set properties:
In next step, I will make some blood on man's neck. Choose the layer of man, use lasso tool (L) to make a selection.
Go to Image -> Adjustments -> Variations for making blood. Click on "more red","lighter" or "darker" to choose blood color that you want.
Press Ctrl+J to duplicate the area of blood. Name this layer is "blood". Go to Filter -> Stylize -> Emboss.
Set "blood" layer to Hue, opacity 100%.
And you will get the final result like this:
