Zygraats largely resembled a bird of prey, such as a hawk, but had six legs. Their underbelly was like that of a spider and they also had a grey, spider-like abdomen. Inside their beaked mouths a series of tiny, hollow fangs ran along both ridges of their jaw.
The spider-like abdomen of these creatures contained a milky fluid that coalesced into silky threads upon exposure to air. This allowed them to form large webs that were very strong, but not sticky. While perched they could project this thread as a stream directly at creatures from up to 50 feet (15 meters) away, thereby trapping them, which is a tactic it often used when hunting away from its lair.
Zygraats tried to trap wandering prey in net-like barriers of their silk webbing and would then swoop down to bite them with their poisonous fangs.
It was rare to encounter male specimens of this species, for female zygraats devoured them during the mating process. They laid around six to thirty six egg sacks.
Zygraats were a carnivorous species that preferred relatively small prey. A nesting zygraat often had a larder of fresh meat to feed their young.
Zygraats were only known to be found in isolated forest regions. They laid their egg sacks in web-like nests built high atop trees or along rocky cliffsides. They sometimes used bits or clothing or other material when constructing their nests and would secure brightly colored bits of cloth to 
The milky fluid within the abdomen of these creatures was prized as an alternative material component for the spell web that made the web produced by the spell harder for creatures to escape from. An abdomen contained enough fluid for three such uses. In addition, some creatures fashioned the webs of zygraats into robes.
- Tim Beach, Donald J. Bingle, Al Boyce, Vince Garcia, Kris Hardinger, Steve Hardinger, Rob Nicholls, Wes Nicholson, Norm Ritchie, Greg Swedberg, and John Terra (1992). Monstrous Compendium Fiend Folio Appendix (MC14). (TSR, Inc), p. 63. ISBN 1-56076-428-7.
- Ed Greenwood (March 1993). “Campaign Guide to Myth Drannor”. In Newton H. Ewell ed. The Ruins of Myth Drannor (TSR, Inc.), p. 12. ISBN 1-5607-6569-0.
- Eric L. Boyd (1998). Demihuman Deities. (Wizards of the Coast), p. 97. ISBN 0-7869-1239-1.
Magical spiders: Bloodsilk spider • Electric spider • Glass spider • Gaze spider • Goblin spider • Pet of Kalistes • Spellgaunt • Steeder
Planar spiders: Demonweb terror • Fire spider • Myrlochar • Phase spider • Tomb spider • Vortex spider
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