Multiattack

Two Beak attacks and one Tentacles attack.

Beak

Melee Weapon Attack: +10 to hit, 10 ft., one target, 21 (3d10+5) piercing damage + 9 (2d8) poison.

Tentacles

Melee Weapon Attack: +10 to hit, 30 ft., one target, 18 (2d12+5) bludgeoning damage and target is grappled (escape DC 18). Until this grapple ends target is restrained nautiloid can automatically hit target with its Tentacles and nautiloid can't make Tentacles attacks vs. other targets.

Jet Propulsion (Recharge 5-6)

Releases a magical burst of pressure that propels it backwards in a line that is 90' long and 10 ft. wide. Each creature within 15 ft. of the space the nautiloid left and each creature in that line must make a DC 18 Con save. On a failure a creature takes 45 (10d8) force and is pushed up to 20' away from the nautiloid and knocked prone. On a success a creature takes half the damage but isn't pushed or knocked prone.