Multiattack

The watcher makes four attacks with its tentacles.

Tentacle

Melee Weapon Attack: +13 to hit, reach 20 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage, and the target is grappled (escape DC 17). Until this grapple ends, the target is restrained. Each of its four tentacles can grapple one target.

Paralyzing Gaze (Recharge 5-6)

The watcher can target one creature within 60 feet with its eerie gaze. The target must succeed on a DC 19 Wisdom saving throw or become paralyzed for 1 minute. The paralyzed target can repeat the saving throw at the end of each of its turns, ending the effect on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to the watcher's gaze for the next 24 hours.