Ahlkoth

Spider Climb. Ahlkoth can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Sense. While in contact with a web, Ahlkoth knows the exact location of any other creature in contact with the same web.

Web Walker. Ahlkoth ignores movement restrictions caused by webbing.

Ambusher. Ahlkoth has advantage on attack rolls against any creature it has surprised.

Arachnophobia Aura. Any creature of Ahlkoth's choice, that starts its turn within 30 feet of Ahlkoth and can see or hear it must succeed on a DC 14 Wisdom saving throw or become frightened of Ahlkoth. A frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to this aura for the next 24 hours.

Fade Away. After taking an action. Ahlkoth automatically takes the Disengage action

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one creature. Hit: 24 (4d8 + 6) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 16 (3d10) 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.

Stinger. Melee Weapon Attack:  +8 to hit, reach 10 ft., one restrained creature. Hit: 17 (2d10+6) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 22 (4d10) poison damage on a failed save and becoming poisoned, or half as much damage on a successful one. 

Web. Ranged Weapon Attack: +8 to hit, range 40/80 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 18 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).

Skitter. Ahlkoth moves up to its movement.