Monster Manual, page 173
Stone Camouflage. The grick has advantage on Dexterity (Stealth) checks made to hide in rocky terrain.
Multiattack. The grick makes two attacks: one with its tail and one with its tentacles. If it hits with its tentacles, the grick can make one beak attack against the same target. Tail. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage. Tentacles. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 22 (4d8 + 4) slashing damage. Beak. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 4) piercing damage.
Forest, Underdark