I guess I'll close with my own entry. I've been thinking of a place lately, which I simply refer to as the dream factory.
The dream factory is, of course, a city in which all dreams of all the people of Earth are manufactured. It lies in a plane of existence just beyond conscious awareness of the typical human, though lately humans have begun slipping into it through holes in the interplanar matter.
The buildings in the city all look relatively similar: jet-black, obsidion-like structures which range in size from only a few stories to stretching far beyond sight into the sky. Between these buildings stretch perfectly straight roads which look nearly identical to our own, though they are slightly soft and sticky to the touch as if made from the exposed flesh of a living creature. However, the sky is what really sets the dream factory apart. Ever-changing in color, the sky produces a soft glow that does very little to illuminate the ground below. What does the color come from? It's produced by the billions and billions of butterflies created from the leftover spiritual energy of the deceased, all flocking together in a giant, all-encompassing cloud. As depressing as it may seem, it is a mercy, as the cloud prevents any observers from seeing the true sky: an infinite void where the souls of the dead go to be shredded and scattered.
The world seems dead, but as of yet it is merely dying. At the center of the city, a panel of the same black which composes the building stretches along a 40 ft diameter circle in the ground. This panel is just thin enough for a careful observer to barely make out the shape of a pulsing, fleshy sphere several hundred feet below the surface--the heart of the factory. What the observer wouldn't notice is the blackish-green veins which wrapped around the heart, piercing into its weakest spots and corrupting the dreams it creates to form nightmares.
The nightmares all have physical form while within the factory, only becoming what we know of them once they invade our dreams. Having specific targets, they typical manifest the regrets, fears, and hates of their intended victims, though they have been known to gain new attributes when encountered by a stray human who slips into the factory.
One nightmare is the Threader, who's target is 31 yr old Victoria, a bald, albino woman who is still haunted by the mother who treated her like a porcelain doll, even going so far as to attempt to stitch new hair into her head. The Threader is a relatively tall nightmare, standing at ~6 ft tall with the aid of its tall-yet skinny jointed legs. What could pass for a head sits as it would on a human, though the only feature on it is a wide, slit-like mouth which opens to reveal absolutely nothing--no teeth, no tongue, only darkness. Coming from its shoulders are two thin raptor-like arms which lead to long, hollow claws. The Threader's back has a vertical slit, from which come writhing threads capable of shredding and absorbing flesh which lead into the claws. The Threader, while not particularly fast, is incredibly intelligent. If it can't outrun its victim, it will herd it into a dead end or cut it off using connecting paths. With its victim trapped, it will dig its claws into the victim's head, allowing the threads to dig in and work their ways throughout the entire body, shredding and eating away at the person from the inside. Since its hide is nearly impenetrable, the only probable way to defend yourself against the Threader is to sever the threads from the claws to prevent it from threading you, then working your way behind it to stab into the slit of its back.