Chaos Gaze. When a creature starts its turn within 30 feet of the abyssal hulk and is able to see the abyssal hulk’s eyes, the abyssal hulk can magically force it to make a DC 18 Charisma saving throw, unless the abyssal hulk is incapacitated.

On a failed saving throw, the creature can’t take reactions until the start of its next turn and rolls a d8 to determine what it does during that turn. On a 1 to 4, the creature does nothing and looses concentration on anything they are doing. On a 5 or 6, the creature takes no action but uses all its movement to move in a random direction and doesn't care how dangerous the way is not stopping shoving anything out they way if it has too. On a 7 or 8, the creature makes one melee attack against a random creature, or it attacks itself. 

Unless surprised, a creature can avert its eyes to avoid the saving throw at the start of its turn. If the creature does so, it can’t see the abyssal hulk until the start of its next turn, when it can avert its eyes again. If the creature looks at the abyssal hulk in the meantime, it must immediately make the save.

Acidic blood. When a creature deals piercing or slashing damage with a melee attack to the abyssal hulk they take 2 (1d4) acid damage. 

Tunneler. The abyssal hulk can burrow through solid rock at half its burrowing speed and leaves a 5 foot-wide, 8-foot-high tunnel in its wake.

Multi attack. The abyssal hulk makes two claw attacks and one acid spew attack. 

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., 1 target. Hit: 18 (2d10 + 8) [slashing] damage. 

Acid spew. RangedWeapon Attack: +8 to hit, range 10/25 ft., 1 target. Hit: 18 (2d10 + 8) [acid] damage.