Shapechanger. The shade stalker can use its action to polymorph into a Medium-sized shadow or back into its true form, which is humanoid. Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Shadow Blend. While in dim light or darkness, the shade stalker can use a bonus action to become invisible until it moves or takes an action.

Sunlight Sensitivity. While in sunlight, the shade stalker has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Multiattack. The shade stalker makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 11 (2d6 + 4) piercing damage, and the target must make a DC 12 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much on a successful one. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 9 (2d4 + 4) slashing damage.

Shadowstep (Recharge 4-6). The shade stalker magically teleports to an unoccupied space it can see within 60 feet of it.