Confusing Gaze. When a creature starts its turn within 60 feet of the Abberumbra Hulk and is able to see the Abberumbra Hulk's eyes, the Abberumbra Hulk can magically force it to make a DC 17 Charisma saving throw, unless the Abberumbra 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. On a 5 or 6, the creature takes no action but uses all its movement to move in a random direction. On a 7 or 8, the creature makes one melee attack against a random creature, or it does nothing if no creature is within reach.

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 Abberumbra Hulk until the start of its next turn, when it can avert its eyes again. If the creature looks at the Abberumbra Hulk in the meantime, it must immediately make the save.

Many Eyes. The Abberumbra Hulk cannot be surprised, even while unconscious, and has advantage on sight-based ability checks or saving throws. Additionally, the Abberumbra Hulk's eyes cover it's body, and the only way for a creature to avert it's gaze is by shutting it's eyes. 

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

Multiattack. The Abberumbra hulk makes three attacks: two with its claws and one with its mandibles or it's tentacle. 

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: (2d8 + 6) slashing damage.

Mandibles. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: (3d8 + 6) slashing damage.

Tentacle. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: (2d8+6) bludgeoning damage, and must succeed on a DC 16 Strength saving throw or become Grappled. The Abberumbra Hulk can only Grapple one creature at a time. 

Aberration Mutation. When a creature the Abberumbra Hulk can see ends it's turn within 60 feet of the Abberumba Hulk, the Abberumbra Hulk can force that creature to make a DC 17 Wisdom saving throw, or become frightened until the start of their next turn. 

Strange Tentacle. When a creature enters the Abberumbra Hulks melee range, it can make an attack with it's Tentacle.