Death Shriek. When the namorrodor is reduced to 0 hit points, it lets out an agonizing shriek as it melds back into the feywild. All creatures within 60 ft. of the namorrodor that can hear are deafened for 1d4 minutes, and they each take 9 (2d8) thunder damage, or half as much on a successful DC 13 Dexterity saving throw.

Keen Hearing and Smell.  the namorrodor  has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Lifeforce Sense. The namorrodor is able to sense creatures within five miles of its location that are close to death (below 25% of their maximum HP), and it has ethereal sight.

Sunlight Vulnerability. While in sunlight, the shadow mauler loses its damage resistances and condition immunities. It also has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Multiattack. 

The namorrodor makes two attacks with its claws. or one with a claw and bite

Claw.  Melee Weapon Attack: +6 to hit, reach 5 ft., one target. 

Hit: 10 (1d12 + 4) slashing damage. If the target hit by this attack has less than half its hit point maximum, the attack is a critical hit. 

Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 3) piercing damage.

black spit. +5 the namorrodor can spit a black substance that when shout at the eyes can temporarily blind a creature 1d4 minutes 

Shadow Leap. As a bonus action, the namorrodor can leap into a shadow and can teleports up to 30 ft. to an unoccupied space that is also in shadow.