Shadow

Medium Undead, Chaotic Evil

AC: 12

Initiative: +2 (12)

HP: 27 (5d8 + 5)

Speed: 40 ft.

STR: 6 (-2)
DEX: 14 (+2)
CON: 13 (+1)
INT: 6 (-2)
WIS: 10 (+0)
CHA: 8 (-1)

Skills: Stealth +6

Vulnerabilities: radiant

Resistances: acid; cold; fire; lightning; thunder

Immunities: necrotic; poison

Condition Immunities: exhaustion; frightened; grappled; paralyzed; petrified; poisoned; prone; restrained; unconscious

Senses: Darkvision 60 ft., Passive Perception 10

CR: 1/2 (XP 100; PB +2)

Habitat: Planar, Shadowfell, Underdark, Urban

Amorphous.

The shadow can move through a space as narrow as 1 inch without expending extra movement to do so.

Sunlight Weakness.

While in sunlight, the shadow has Disadvantage on D20 Tests.

Actions

Draining Swipe.

Melee Attack Roll: +4, reach 5 ft. Hit: 5 (1d6 + 2) Necrotic damage, and the target's Strength score decreases by 1d4. The target dies if this reduces that score to 0. If a Humanoid is slain by this attack, a Shadow rises from the corpse 1d4 hours later.

Bonus Actions

Shadow Stealth.

While in Dim Light or Darkness, the shadow takes the Hide action.

Find this creature in the encounter builder

Source: Stranger Things: Welcome to the Hellfire Club, p. 272 - Licenses and attribution