Arachnarok Spider

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.

Multiattack. The Arachnarok makes 3 attacks, one with its Bite and two with its massive legs.

Massive Legs. Melee Weapon Attack: +9 to hit, reach 10ft., one creature. Hit:  23 (3d10 + 6) slashing damage.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 11 (2d8 + 2) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 14 (3d8) 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). 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 14 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 12; hp 7; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).