Constrainer

Grasping Tendrils. The Constrainer can have up to six tendrils at a time. Each tendril can be attacked (AC 20; 10 hit points; immunity to poison and psychic damage). Destroying a tendril deals no damage to the Constrainer, which can extrude a replacement tendril on its next turn. A tendril can also be broken if a creature takes an action and succeeds on a DC 15 Strength check against it.

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

Petrifying Gaze. If a creature starts its turn within 30 feet of the Constrainer and the two of them can see each other, the Constrainer can force the creature to make a DC 16 Constitution saving throw if the Constrainer isn't incapacitated. On a failed save, the creature magically begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.

A creature that isn't surprised can avert its eyes to avoid the saving throw at the start of its turn. If it does so, it can't see the Constrainer until the start of its next turn, when it can avert its eyes again.

Multiattack. The Constrainer makes four attacks with its tendrils, uses Reel, and makes one attack with its bite.

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 24 (4d8 + 6) piercing damage plus 7 (2d6) poison damage additinally a creature that too the poison damage needs to make a DC 13 constitution save or become poisoned.

Tendril. Melee Weapon Attack: +7 to hit, reach 50 ft., one creature. Hit: The target is grappled (escape DC 18). Until the grapple ends, the target is restrained and has disadvantage on Strength checks and Strength saving throws, and the Constrainer can't use the same tendril on another target.

Reel. The Constrainer pulls each creature grappled by it up to 30 feet straight toward it.