Multiattack

Briny Embrace if it has a creature grappled. Then two Claws or one Bite and one Claw.

Bite

Melee Weapon Attack: +6 to hit, 5 ft., one target, 13 (2d8+4) piercing damage.

Claw

Melee Weapon Attack: +6 to hit, 5 ft., one target, 11 (2d6+4) slashing damage and target is grappled (escape DC 14). It has two claws each of which can grapple only one target.

Briny Embrace

Fills lungs of a creature grappled by it with seawater. Creature: DC 14 Con save or begin suffocating. A suffocating but conscious creature can re-save at end of each of its turns success ends effect on itself. Effect also ends if creature escapes grapple.

Whispered Terrors (Recharge 5-6)

Bombards the minds of up to 3 creatures it can see within 60' of it with nightmares: 18 (4d8) psychic and frightened until end of its next turn (DC 14 Wis half not frightened). If creature fails by 5+ also suffers short-term madness.