Coma Cobra

Constrict. The cobra makes a strength check against their opponent's strength save. If the cobra succeeds, the target is restrained. If the cobra is bloodied, from this position, the cobra will put its fangs to the enemy's throat, in a gesture that it is taking the enemy hostage. From this position, the constricted creature takes half of all damage dealt to the cobra, its bite does crit damage to the constricted creature, and the cobra can use its reaction at any time to bite the constricted creature. If it wishes, it can use its action on subsequent turns to deal 1d6+2 damage automatically to the constricted creature.

Bite. Melee Attack: +4 to hit, reach 5 ft., 1 target. Hit: # (2d6 + 7) poison and piercing damage. 

Sedating Spray 1/day. Ranged Attack: DC 15 Con save, range 15 ft., 1 target. On a failure:  2d4+1 poison damage. Additionally, the target gains one level of exhaustion, and must make this saving throw four more times, each at the end of their turns, each failure adding an additional 2d4+1 damage and one more level of exhaustion. Succeeding after failing the first time does not stop them from needing to make the save again, until five total saving throws have been made. An item or ability that cures poison stops them from needing to save any more, but does not remove the exhaustion unless the item or ability specifically says it can. If combat ends before all saving throws are made, make the rest either in a turn based manner if the other players want to stop them, or in quick succession if they can't.