Multiattack

The lunarchidna makes two attacks: one with its bite and one with its claws. If the lunarchidna hits a Medium or smaller target with both attacks on the same turn, the target is restrained by webbing and the lunarchidna uses Wrap Up.

Bite

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) necrotic damage. The target must succeed on a DC 13 Constitution saving throw or its hp maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hp maximum to 0.

Claw

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) slashing damage.

Web (Recharge 5-6)

Ranged Weapon Attack: +5 to hit, ranged 30/60 ft., one creature. Hit: The target is restrained by webbing. As an action the restrained target can make a DC 13 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 5; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

Wrap Up

The lunarchidna wraps up a Medium or smaller creature restrained by webbing. The wrapped target is blinded, restrained, and unable to breathe, and it must succeed on a DC 13 Constitution saving throw at the start of each of the lunarchidna's turns or take 5 (1d4 + 3) bludgeoning damage. The webbing can be attacked and destroyed (AC 10; hp 15; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage). The lunarchidna can have only one creature wrapped at a time.