Giant Spider

The giant spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

While in contact with a web, the giant spider knows the exact location of any other creature in contact with the same web.

The giant spider ignores movement restrictions caused by webbing.

Melee Weapon Attack: +5 to hit, reach 5 ft.. Hit: 7 (1d8 + 3) piercing damage.
The target must make a DC 11 Constitution saving throw, taking 9 (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.

Recharge 5–6. Ranged Weapon Attack: +5 to hit, range 30 ft.. 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).