Spider Climb. The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Web Sense. While in contact with a web, the spider knows the exact location of any other creature in contact with the same web.
Web Walker. The spider ignores movement restrictions caused by webbing.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 7 (2d6+6) 1d8+3 piercing damage; on a hit, it grapples (escape DC 15) and the target must make a DC 16 Constitution saving throw, taking 11 (2d10) 2d8 poison damage on a failed save, or half as much damage on a successful one. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.
Web (Recharge 5-6 1d6 ). Ranged Weapon Attack: +5 to hit, range 30/60 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 12 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 5; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).
To snare its prey, a giant spider spins elaborate webs or shoots sticky strands of webbing from its abdomen. Giant spiders are most commonly found underground, making their lairs on ceilings or in dark, web-filled crevices. Such lairs are often festooned with web cocoons holding past victims.
Underdark (Brightdark, Underdark, Deepdark)