Darkweavers had an amorphous form, hidden underneath folds of darkness that clung to them like a cloak. Underneath this darkness its true form was a grey, fleshy body that vaguely resembled a spider and was split into two segments. The first segment had clusters of spider-like eyes on all sides and a fanged mouth on the underside. Both segments had four tentacles each; darkweavers normally walked on all eight tentacles but could rear back on the second set of four to allow use of the front set in fighting or manipulating objects. Each of these tentacles was 10 feet (3 meters) in length.
Darkweavers were solitary creatures of sinister motives.
Darkweavers were able climbers, possessed darkvision, and a form of telepathy that allowed them to communicate with each other from a distance of up to 60 feet (18 meters). They also healed remarkably fast and could regrow lost tentacles within a day. Darkweavers had innate spell-like abilities that allowed them to replicate the effects of the spells confusion, darkness, tongues, web, and suggestion three times each day, as well as the spell shadow walk once each day.
In areas of darkness or shadow a darkweaver was capable of creating two to five mirror images of itself, as well as casting abilities that replicated the effects of the spells shades, solid fog, and symbol of despair once per day. 
Darkweavers could also travel between shadows in a way that was similar to the dimension door spell. A darkweaver could use this ability to travel up to a total distance of 320 ft (98 m) each day, split into increments as small as 10 ft (3 m). The creatures were covered in natural armor made out of shadow-stuff; it aided them in hiding in shadows.
By far the most potent ability of darkweavers were the shadowy, semi-solid strands that perpetually surrounded them for 60 ft (18 m). This web, of sorts, provided concealment to all creatures within it, even from creatures with darkvision or blindsight. Only truesight allowed for normal vision. The web also prevented creatures that entered its area from going any direction other than that of the darkweaver. Darkweavers were naturally immune to the effects of their own and others' webs.
After the city of Elgrin Fau had been abandoned by its inhabitants, one inhabitant by the name of Kesson Rel returned and opened a gate in the middle of the necropolis to taunt the dead interred there. Over this gate he installed a darkweaver to act as a guard.
Darkweavers were native to the Plane of Shadow, and they fed on the strength of other creatures. Although solitary by nature, they would sometimes enslave dangerous carnivores or evil creatures by bringing them the still-living corpse of its own prey, ensnaring the creature when it approached, and then allowing it to eat the corpse. Darkweavers would repeat this until the creature in question came to rely on it for food or view it as an ally.
These creatures asexually reproduced by division, though this was a rare occurence.
Being inhabitants of the Plane of Shadow, these creatures preferred to lair in places where sunlight was never visible. Such as dismal swamps, gloomy forests, and underground passageways.
- Dawn of Night
- Eric Cagle, Jesse Decker, James Jacobs, Erik Mona, Matthew Sernett, Chris Thomasson, and James Wyatt (April 2003). Fiend Folio. (Wizards of the Coast), pp. 39–41. ISBN 0-7869-2780-1.
- Richard Baker (October 1995). Monstrous Compendium Planescape Appendix II. Edited by Karen S. Boomgarden. (TSR, Inc.), pp. 20–21. ISBN 0-7869-0173-X.
- Paul S. Kemp (June 2004). Dawn of Night. (Wizards of the Coast), pp. 85, 93. ISBN ISBN 0-7869-3225-2.
- Dale Donovan (December 1995). “Liber Benevolentiae”. In Michele Carter ed. Planes of Conflict (TSR, Inc.), p. 6. ISBN 0-7869-0309-0.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), pp. 148–150. ISBN 0-7869-3919-2.
Magical spiders: Bloodsilk • Electric • Glass • Gaze • Goblin • Pet of Kalistes • Spellgaunt • Steeder
Planar spiders: Demonweb terror • Fire • Myrlochar • Phase • Tomb • Vortex
Constructs: Arachnar • Bone spider • Jade spider • Retriever • Spiderwalker • Stone spider
Creations of Lolth: Abyssal widow • Chwidencha • Drider (Vampire) • Shunned
Outsiders: Bebilith • Darkweaver • Greelox • Inferno spider • Yochlol
Humanoids: Aranea • Chitine • Choldrith • Ettercap • Werespider
Miscellaneous: Kitthix • Neogi • Rhylfang • Susurrus
Undead spiders: Wraith spider