I wasn't happy with the barrier on the door and the poster so I decided to paint over them. I wanted the scene to feel like it was at night so I shaded the whole image using the Level Correction tool. To imply that the scene is light by some street lights I added two big diagonal shadows on the top of the images. I created a new layer, drew in the shape with the Selection tool and filled the selection with a dark brownish tone. The layer was then set to Multiply and the Opacity was set to roundabout 45 - 50%. For a three-dimensional feeling I selected the shadow area on the inner side of the window and moved it downwards a bit. I used the color balance adjustment to shift the greenish tones to blue (Fig.10).
Second Creature and Refining
After a short break from this image I decided to add a second creature, which, in my opinion, added a lot to the eerie feeling. I duplicated the first creature (another good reason to keep some elements on a separate layer) and moved it to the lower area of the image. To make sure that the second creature didn't look like a copy I used the Liquify tool and Transformation tools to create a new body shape. By using the Eraser tool I got rid of the unnecessary elements and painted in some new shapes like the arm and the smoky body (Fig.11).
Final Details and Color Grading
Now the image was close to finished. I created a new layer and started to paint in some bright highlights on the creatures. For the eyes I created a second layer, which was set to Add. I used a Soft Round brush twice the size of the eyes with a pretty bright value and painted in the glow of the eyes. To get the right look you could play around with the opacity of the layer. I used a custom cloud brush to paint in the foggy bodies. To add more of an atmosphere to the painting I created a new layer and painted in some fog using a cloud brush. Last but not least, I used the Color Balance tool for subtle color shifting. Finally I added Soft Light layers with a red and green tone to add warmth and contrast (Fig.12).