Arachnea, Amethyst Queen

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

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

Web Walker. Arachnea ignores movement restrictions caused by webbing.

Lethal Venom. Whenever Arachnea applies the poisoned effect to another creature, that creature will take 2(1d4) poison damage at the end of it's turn for 30 seconds (5 turns) or until the poisoned effect ends.

Ironsilk. Any web that Arachnea produces is exceptionally sturdy, and is capable of holding the weight of 1 medium creature.

Spidercall (Recharge 7–8). Arachnea summons spiders to aid her. She will summon 4 (2d4 - 1) spiders to her aid.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 5 (1d4 + 3) piercing damage and the target must make a DC 14 Constitution saving throw. On a failed save, the target takes 10 (2d8+1) poison damage and becomes poisoned, or half as much damage on a successful one. 

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 15 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 13; hp 7; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

Silkbind. If Arachnea is hit by an attack that does not do fire damage, she can use the bound silk on her back to protect herself, halving the damage of the attack.

Arachnea can only preform a legendary action once her HP is lower than half of her maximum HP and she can only preform 2 legendary actions per day.

Cocoon (Costs 3 Actions). Arachnea encases herself in a cocoon of ironsilk over the course of her next 3 actions. Her AC will increase by 2 for every turn that passes while Arachnea is doing this. Should Arachnea manage to fully encase herself in ironsilk, she will heal for 6 (1d12) HP every turn she spends inside the cocoon. While inside the cocoon, Arachnea will be considered restrained and will have immunity to bludgeoning, poison and psychic damage until she is broken free, or until she breaks free herself. If Arachnea is successfully hit for at least 7 damage while she is making the cocoon, she will fail at making the cocoon and will be stunned for her next turn. The completed cocoon has an HP of 15 (2d10 + 4) and will break once the cocoon's HP is depleted to 0.