Fiendish Giant Spider

Medium Beast, Unaligned

STR
12 (+1)
DEX
16 (+3)
CON
13 (+1)
INT
3 (-4)
WIS
12 (+1)
CHA
4 (-3)
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.

Actions

Bite.

Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 4 (1d6 + 1) piercing damage, and the target must make a DC 11 Constitution saving throw, taking 7 (2d6) 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.

Find this creature in the encounter builder

Fiendish Giant Spider

Source: Out of the Abyss, p. 97 - Licenses and attribution