Multiattack. The grick makes one Beak attack and one Tentacles attack.
Beak. Melee Attack Roll: +4, reach 5 ft. Hit: 9 (2d6 + 2) Piercing damage.
Tentacles. Melee Attack Roll: +4, reach 5 ft. Hit: 7 (1d10 + 2) Slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 12) from all four tentacles.