Shadow Thief

Small aberration, neutral

Armor Class 13
Hit Points 27 (6d6 + 6)
Speed 30 ft.

STR	DEX	CON	INT	WIS	CHA
12 (+1)	16 (+3)	12 (+1)	13 (+1)	12 (+1)	14 (+2)

Skills Deception +4, Stealth +5
Senses darkvision 90 ft., passive Perception 11
Languages Common, Deep Speech
Challenge 1 (200 XP)
Proficiency Bonus +2

SPECIAL TRAITS

• Coalesce Memories. When a creature the shadow thief is merged with makes an Intelligence ability check to recall knowledge, the shadow thief must make a Charisma saving throw. If the result of the saving throw is less than that of the creature’s Intelligence check, the shadow thief’s Penumbral Theft ability ends.

ACTIONS

• Claw. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) slashing damage plus 3 (1d6) cold damage.
• Penumbral Theft. The shadow thief magically absorbs the shadow of a creature within 5 feet of it. The creature must succeed on a DC 12 Wisdom saving throw. On a failure, the shadow thief merges with the creature. While merged with the shadow thief, the creature’s shadow moves erratically, causing the creature to make Dexterity (Stealth) checks with disadvantage. The shadow thief can’t be targeted by any attack, spell, or other effect while merged, but it can be affected by spells like protection from evil and good. The shadow thief cannot take actions or reactions while merged, except to Swap Shadows or Coalesce Memories or to end the merge as an action. The merge also ends if the creature is reduced to 0 hit points. An affected creature can be identified as such by their shadow’s oddities with a successful DC 15 Intelligence (Arcana) or Wisdom (Perception) check. The creature can repeat the saving throw after every 24 hours, ending the effect on a success. After three successive failures, the merge lasts indefinitely.

REACTIONS

• Darkness Dissolution (1/Day). When damage would reduce the shadow thief to 0 hit points, the thief remains at 1 hit point and magically teleports to an area of darkness it can see within 1,000 feet. If it can’t teleport in this way, it dies.
• Swap Shadows. When a Tiny creature the shadow thief is merged with moves within 5 feet of a larger creature, the shadow thief uses Penumbral Theft on the larger creature, which makes its Wisdom saving throw against the effect with disadvantage.

ABOUT

One of the many creations of the unfathomable denizens of the distant cosmos, shadow thieves are small creatures with strangely angular bodies that lie underneath a veil of shadow. Despite the aura of dusk that perpetually surrounds them, shadow thieves are corporeal and remain as such even when they merge with a mortal creature to steal the mortal’s shadow.

Shadow thieves were initially created to gather information for their alien masters. By assuming the form of different mortal creatures’ shadows, a shadow thief could infiltrate society via progressively more important figures. At least, this was their creators’ intention. However, as the first shadow thieves traveled through the vastness of space, they lost their connection to their elder creators but not their interest in the societies of mortals. Now they wander the planet with their own mysterious designs in mind.

The experience of having one’s shadow stolen by a shadow thief is not pleasant but stories exist of mortals who form friendships with shadow thieves, willingly allowing the monsters to accompany them on their journeys. For unwilling hosts, the easiest way to rid oneself of a shadow thief is to offer the being a tantalizing morsel of knowledge.