Broodmother

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.

Immunities: Poison , Acid

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 7 (2d10 +5) piercing damage, and the target must make a DC 17 Constitution saving throw, taking 9 (4d8) 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 12 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 25 vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

Dash if on webbed terrain 

Webbed up: The broodmother can use its reaction to shoot a web at a target 

Legendary actions

New birth: The Broodmother can create a swarm of spiders at her command 

Children of the swarm: The broodmother calls upon a giant spider to appear the more damage she takes connoted by every 50 hit points is the number that she summons

Snatch & Grab: If a target is restrained by webbing and the brood mother is underground The brood mother can grab and drag them under