Fenrir (http://www.pantheon.org/articles/f/fenrir.html)
The Wolf, Destroyer of the Sun.
There is on the layer of Colthys a realm nestled in a deep divide between two mountians. Looking like a great power had reached down to stab the crevice between two hard rocks, the slot canyon* found here is shielded from sight until one is almost right on top of it. Within the canyon the light is very dim and faintly red shifted.
Climbing down (there is no easy entrance), a wanderer will begin to encounter threads, feeling almost like dry non-sticky spider webs. Thin and appearing fragile, these threads are as strong as steel and will support weight allowing the daring adventurer to use them to cross the canyon. Like many things in Carceri though, they are not to be trusted and seemingly thick portions may suddenly give way plummetting the unwary traveller into the depths of the canyon. Once within the thick of the webs it becomes a challenge to climb or cut your way out of them.
If a traveller manages to make his way down to the canyon's surface below, he will need to bring his own light with him. The webs obscure the light from above entirely, and as they coat the walls of the canyon, do a good job of obscuring any of the red light of Carceri that may emminate from the rocks themselves.
Once on the canyon floor though, one will become aware of the breath of movement through the webs, rippling the threads in a steady in and out flow of wind that originates from the center of the canyon. Approaching the center of the canyon the wind becomes more clearly that of the breath of some grand creature - foul with a lingering scent of rotting flesh. The sharp nosed may catch a scent of human flesh rotting in this wind.
At the center of the canyon, enwrapped in the threads of this web is a giantic wolf form sprawling from one side of the canyon to another. The corporeal form of Fenrir, the Wolf of the norse pantheon who bit off the hand of Tyr. In fact, he's still crunching away on it as the flesh rots between his teeth. The creature bound here is essentially powerless outside of the immediate vicinity of his canyon so any who approach should be extremely cautious. Within close (half mile) range though, Fenrir could be said to have control of a realm on a level equilivant to that of a deity.
The webs are the ribbons that bind him, composed of "the footstep of a cat; the roots of a mountain; a woman's beard; the breath of fishes; the sinews of a bear; and a bird's spittle". They are certainly the only thing keeping him locked in the canyon. There are a few brave or foolhardy souls who will collect the webs for their own uses. The webs make the strongest rope, and are said to powerfully enhance enchantment and binding magics. Unfortunately since they are the only thing keeping the Wolf in check, taking the threads will certainly anger the Norse, and possibly weaken the bindings on the Wolf.
In the coming Ragnarock, when according to legend the Norse pantheon will be destroyed, Fenrir is said to break free of his bonds and join the side of the giants who will war with the Norse pantheon. By legend, he is to eat the sun in the course of the coming battle before exacting his vengence on those who emprisoned him. The darks hold that he may just swing by the Inner Planes to snuff out the Plane of Fire** before heading to Ysgaard.
* http://www.americansouthwest.net/slot_canyons/misery_canyon/photographs.html
** Perhaps by means of Entropes?
Very interesting take on Fenrir's cage. I like it. I also like the part about blowing out the plane of fire instead of the sun. Clever.
