Behir, dryk

Lightning Reflexes. The dryik can take the Dash or Disengage action as a bonus action on its turn.

Multiattack. The dryik makes two attacks: one with its bite and one to constrict.

Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 12 (2d8 + 3) piercing damage, plus 3 (1d6) lightning damage.

Constrict. Melee Weapon Attack: +6 to hit, reach 5 ft., one Large or smaller creature. Hit: 9 (1d10 + 3) bludgeoning damage plus 9 (1d10 + 3) slashing damage. The target is grappled (escape DC 15) if the behir isn't already constricting a creature, and the target is restrained until this grapple ends.

Lightning Jolt (Recharge 6). When the dryik is struck by a melee attack, as a reaction, the dryik unleashes a burst of electrical energy. Every creature within 10 feet of it must make a DC 15 Constitution saving throw. On failed save, a creature takes 27 (5d10) lightning damage and is stunned until the end of the dryik's next turn. On a successful save, a target takes half as much damage and isn't stunned.

Crush(Costs 3 actions). After the dryik can attempt to crush any creature that it has grappled. The grappled creature must succeed on a DC 15 Strength Saving throw. On a failed save, the target takes 19 (3d10 + 3) bludgeoning damage and has disadvantage on Strength (Athletics) checks to escape grapples until the end of its next turn.

Bite (Costs 2 action). Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 12 (2d8 + 3) piercing damage, plus 3 (1d6) lightning damage.

Move (Costs 1 action). The dryik moves up to half its speed.