20 years ago, my Mom and Sister happened upon 2 demons in our home a few days after a family member had committed suicide. Alone at nighttime after opening the door to the vacant house, the headlights from the vehicle shone through and revealed 2 demons scurrying away, heading for deep shadows elsewhere inside. They both got a real good look at 1 of those demons, and describe him the same way.
I’m not an artist, but if I was, I’d try to sketch him myself. I've looked around the internet at “demon” artwork and haven’t seen anything resembling what they described.
His form was that of a human with a head, torso, arms and legs. He was covered with black fur except for his face and ears which were fleshy, and almost orange with ugly pock-marks. He had green eyes, pointed ears, sharp white teeth and his nose resembled the snout of a fox.
The lines on his face suggested he always made disgusting expressions, and he sneered at them as he hurried into the darkness. When his back was to them, they could still see his eyes through the back of his head, and saw a short tail that curled towards his body.
He was well built – not skinny, and also not fat. He was relatively short, maybe only 4 feet tall. His legs were curled up underneath him, and he didn't use them to move. If he had actually been standing on his legs, he may have been closer to average height; instead, he moved with a motion that resembled how a gorilla seems to rock and roll when traveling quickly. His hands and feet weren't noticeable, and he didn't have horns or anything on top of his head - just black fur.
It would be cool if someone had seen artwork of a demon like this before, or wanted to attempt to draw this creature against a dark backdrop. I could certainly provide more details if anyone was really interested.