For this homemade child Gargoyle Halloween costume I used my son's PJ's as a pattern. I cut out grey stretchy material and sewed it as a one-piece with Velcro on the back. I put a $3 bald cap and $3 elf ears on my son.
I made his wings out of light weight wood trims that builders use on the walls. The "bones" of the wings were made of very small sized dowels. I cut the trim into two pieces, 1 was 1/2 the length of the other. I drilled a hole to join the two pieces and tightened with a nut. This provided the "hinge" of the wing. I hot glued the grey fabric over the wing "skeleton". This had to be light weight enough for my son, who only ways 33 lbs, to wear and maneuver.
I used small picture frame hanging things as the "pulley" system to tie the string through. I duct taped it onto the "elbow" piece of the wood trim. When he pulled the strings, his wings opened up to about 3 ft on each side. His wings were attached to his Dora the Explorer backpack suitcase, which was covered in the same grey fabric. To open and close the wings, I tried a piece of cooking twine to where the picture hanging thing was taped to the elbow of the wing. I crisscrossed it for better pull.
I took and old strap from a gym bag that had two clips on each end. I resized it so it would fit as a belt on my son, duct tape the two ends together (as the front of the belt) so that each clip was facing the other way. I tied two small pieces of dowels to each string so that my son could easily grab the ends to pull open his wings. If he wanted to keep his wings open, he could clip them to the clips on the belt. This kept the wings expanded open and his hands free.
I had him put his hands over the grey fabric and traced it for his gloves. I only gave him 3 fingers. For the tail, I just cut a long piece of fabric and sewed it down the side, getting smaller at the end. I inserted a piece of bent 16 gauge wire into the tail so that it would keep its shape and I could bend his tail up. I used grey cream makeup to cover his face, bald cap, and ears. Then I drew in the face with black cream makeup. I used my kid's old paintbrush who's bristles had been glued stiff (from the kids not cleaning it after they used it) to dab on white cream makeup. The stiff bristles created the stone look. I drew in fangs and traced it with the black paint to make him look more sinister.