Urophion

Detect Life. The urophion can magically sense the presence of living creatures up to 5 miles away. It knows the general direction of living creatures, but not the exact locations.

False Appearance. While the urophion remains motionless, it is indistinguishable from a normal cave formation, such as a stalagmite.

Grasping Tendrils. The urophion can have up to six tendrils at a time. Each tendril can be attacked (AC 20; HP 10; immunity to poison and psychic damage). Destroying a tendril deals no damage to the urophion, 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.

Innate Spellcasting (Psionics). The urophion’s innate spellcasting ability is Intelligence (spell save DC 13). It can innately cast the following spells, requiring no components:

At will: detect thoughts, levitate

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

Multiattack. The urophion makes four attacks with its tendrils, uses Reel, and makes one Bite attack.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 22 (4d8 + 4) piercing damage.

Tendril. Melee Weapon Attack: +7 to hit, reach 50 ft., one creature. Hit: The target is grappled (escape DC 15). Until the grapple ends, the target is restrained  and has disadvantage on Strength checks and Strength saving throws, and the urophion cannot use the same tendril on another target.

Reel. The urophion pulls each creature by its tendrils up to 25 feet straight towards it.

Mind Blast (1/day). The urophion magically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 13 Intelligence saving throw or be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.