Hat and cape have been added using liquify warp tool.
step 5 of 15
Mask is added with brush tool, edging with smudge tool.
step 6 of 15
Horse is now chopped to insert into canvas
step 7 of 15
Skeleton is adjusted to fit onto the horse with scale tool.
step 8 of 15
Dark sky is added with nebulae layer over it for noise. Hat is burned and dodged to shape further.
step 9 of 15
Left arm is shaped with liquify tool to fit on horses neck (reins have been also added with brush tool). Some pelvic bones are shaped with brush tool, scarf will also be added with brush tool. Moon is painted in with VERY large brush tool in bright orange.
step 10 of 15
Fog is softly brushed in over moon and in front of horse with soft gray and white, then softened even more with very soft eraser tool.
step 11 of 15
Red and brown filters have been added over entire canvas after merging.
step 12 of 15
Hand of skeleton source is lassoed and formed around a handle (brushed in) to hold up jack-o-lantern. (Lantern mouth was changed with smudge and brush tools.)
step 13 of 15
Not happy with the face, another face is lassoed and brought in, liquified to look forward more, then hue changed to be merged to rest of canvas.
step 14 of 15
Another layer of the orion source is placed over everything, then reduced just to use the star pattern to finish off the piece.
step 15 of 15
Thanks to a constructive comment, I gave the horse a little more character to go with the rest of the image by slightly liquifying (warp) its nose and neck. Just enough change to look a little more 'unreal' like the rest.