Skulk

Medium humanoid, Chaotic Neutral

Armor Class 14

Hit Points 18 (4d8)

Speed 30 ft.

STR 6 (-2)

DEX 19 (+4)

CON 10 (+0)

INT 10 (+0)

WIS 7 (-2)

CHA 1 (-5)

Saving Throws CON +2

Skills Stealth +8

Damage Immunities radiant

Condition Immunities blinded

Senses darkvision 120 ft., passive Perception 8

Languages understands Common but can't speak

Challenge 1/2

Fallible Invisibility. The skulk is invisible. This invisibility can be circumvented by three things:

The skulk appears as a drab, smooth-skinned humanoid if its reflection can be seen in a mirror or on another surface.
The skulk appears as a dim, translucent form in the light of a candle made of fat rendered from a corpse whose identity is unknown.
Humanoid children, aged 10 and under, can see through this invisibility.

Trackless. The skulk leaves no tracks to indicate where it has been or where it's headed.

Actions

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) slashing damage. If the skulk has advantage on the attack roll, the target also takes 7 (2d6) necrotic damage.

Source

Mordenkainen's Tome of Foes, p. 227