Big AF Cave 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.

Legendary Resistance (3/Day). If the Colossal Spider fails a saving throw, it can choose to succeed instead.

Multiattack. The Colossal Spider makes three attacks: one with its Bite and two with its Claws. It may swap out its Bite attack with either a Poison sting, Web Spray, Pull or Pounce attack. It may replace all these attacks with a Entangle in Webs attack.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 8 (1d8 + 4) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 13 (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.

Claw. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 13 (2d8+4) slashing damage.

Pounce. Special Attack: The Colossal Spider targets one creature within 30 ft. The spider moves to the closest available point in base contact with the target. The target must succeed on a DC 12 Dexterity (Acrobatics) check or be knocked prone and take 7 (1d12) bludgeoning damage.

Poison Sting (Recharge 5–6). (1d6)The Colossal Spider targets one prone creature within 5 ft. The target must make a DC 15 Constitution saving throw, taking 22 (4d8+4) poison damage on a failed save, or half as much damage on a successful one.

Pull. Ranged Weapon Attack: +7 to hit, range 30 ft., one target. Hit: 11 (2d6+4) piercing damage. A strand of webbing wraps around the target. The target must succeed on a DC 15 Dexterity saving throw or be pulled up to 20 ft. toward the Colossal Spider. If the target is pulled within 10 ft. of the spider, it must succeed on a DC 15 Strength check or be restrained by the webbing. A creature can repeat the Strength check at the end of each of its turns, escaping the restraint on a success.

Web Spray (Recharge 5–6). (1d6) Ranged Weapon Attack: +7 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 15 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; 15 hit points; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

The Colossal Spider can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Colossal Spider regains spent legendary actions at the start of its turn.

Claw. The Colossal Spider makes one Claw attack.

Pull. The Colossal Spider uses its Pull attack.

Entangle in Webs (Costs 2 Actions). The Colossal Spider targets one creature within 10 ft. that is restrained or unconscious. The spider wraps the target in thick layers of webbing, reinforcing the restraints. The target remains restrained and can escape only by succeeding on a DC 20 Strength check at the end of its turn. The webbing can also be attacked and destroyed by other creatures (AC 10; 10 hit points; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).