Shadow

Amorphous. The shadow can pass through an opening as narrow as 1 inch wide without squeezing.

Sunlight Weakness. While in sunlight, the shadow has disadvantage on attack rolls, ability checks, and saving throws.

Undead Nature. A shadow doesnt require air, sustenance, or sleep.

Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) necrotic damage and the target makes a DC 12 Constitution saving throw. On a failure the target is cursed until it finishes a short or long rest or is the subject of remove curse or a similar spell. While cursed the target makes attack rolls Strength checks and Strength saving throws with disadvantage. If the target dies while cursed a new undead shadow rises from the corpse in 1d4 hours the corpse no longer casts a natural shadow and the target can't be raised from the dead until the new shadow is destroyed.

Shadow Sneak. The shadow takes the Hide action even if obscured only by dim light or darkness.