Cthulite

Huge Hands. The cthulite has advantage on any saving throws, ability checks, or attack rolls related to grappling a foe.

Multiattack. The cthulite can make two punch attacks.

Punch. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (3d4 + 3) bludgeoning damage. The cthulite can grapple or shove the target instead of dealing damage with this attack. 

Life Drain. Melee Weapon Attack: +8 to hit, reach 5 ft., one target that is grappled by the cthulite. Hit: 21 (6d6) necrotic damage. The cthulite heals for half of the damage dealt by this attack.

Hole in Reality (1/Day). Note: cthulites, and creatures chosen by them when the ability is initially used, are immune to all effects of this ability. The cthulite uses an action to channel necrotic energy into a point in space within 30 feet of it, tearing space at that point creating spherical, 5ft. in diameter Hole in Reality, which attracts every unsecured object and creature within 50 ft. Within this range:

• All creatures must succeed a DC 16 Strength saving throw or be pulled 15 feet closer to the Hole in Reality. This throw is repeated at the end of a creature's turn if it remains within range.
• Any movement towards the Hole in Reality costs half of what it usually would.
• Any creature attempting to move away from the Hole in Reality must succeed a DC 16 Athletics check or they are unable to move away from it.

The cthulite must maintain concentration on this ability, or the Hole in Reality will destabilise and collapse. The Hole in Reality also blocks line of sight as well as all light.

As a bonus action, the cthulite can cause 2 tendrils of necrotic energy to reach out from the Hole in Reality to a creature of its choice within 15 feet of its surface, forcing the target to make a DC 16 Dexterity saving throw, taking 18 (4d8) necrotic damage on a failed save.
If a creature starts its turn inside the black hole or moves into its space for the first time on its turn, they take 36 (8d8) force damage

Retributive Lash. When the cthulite takes damage from a creature within 15 feet of the surface of its Hole in Reality, it can lash out with a tendril of necrotic energy from the Black Hole. This reaction occurs prior to the concentration check that the damage provokes.