Multiattack

The nightgaunt can use its Baneful Presence. It then makes three attacks: two with its clutching claws and one with its barbed tail. If the nightgaunt is grappling a creature, it can use its barbed tail one additional time.

Clutching Claws

Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage, and the target is grappled (escape DC 16) if it is a Medium or smaller creature. Until this grapple ends, the target is restrained. The nightgaunt has two claws, each of which can grapple only one target. While using a claw to grapple, the nightgaunt can't use that claw to attack.

Barbed Tail

Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage plus 10 (3d6) poison damage.

Baneful Presence

Each creature of the nightgaunt's choice that is within 30 feet of the nightgaunt and aware of it must succeed on a DC 16 Wisdom saving throw or have disadvantage on all attack rolls and saving throws 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. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the nightgaunt's Baneful Presence for the next 24 hours.