Cults' Demon Doll of Chaos

False Appearance. While the possessed doll remains motionless, it is indistinguishable from a normal doll.

Demonic Anatomy. Through the twisted and evil knowledge of the demonic spirits that haunt the doll, it knows just how to hurt living creatures and cause the most pain. The doll deals maximized damage to creatures that aren't undead or constructs with its weapon attacks and scores a critical hit on the roll of a 19-20 verses such creatures.

Devious Stealth. The possessed doll has advantage on all dexterity ability checks made to stealth. Additionally, whenever the possessed doll takes the move action during its turn, it can use a bonus action to hide, even if it only is partially obscured such as from a creature at least 1 size larger than it.  

Immutable Form. The doll is immune to any spell or effect that would alter its form.

Magic Resistance. The doll has advantage on saving throws against spells and other magical effects.

Magic Weapons. The dolls weapon attacks are always considered magical.

Small but Deadly. Roll initiative with advantage. 

More the Merrier. Can summon a swarm (ex. Ravens, Rats, etc. Dms choice that's appropriate to setting) 3/day.

Multiattack. The doll makes three attacks one of which can be a Fearful gaze.
Vicious Dagger. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) piercing damage. 

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (1d4 + 1) bludgeoning damage.

Fearful Gaze. One target that the Possessed Doll can see within 60ft makes a Wisdom DC 14 saving throw or becomes frightened for 1 minute. The target can repeat this save at the end of each its turns to end the effect early. 

The doll can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The doll regains spent legendary actions at the start of its turn.

Shadow Voices (1 action). Ghostly whispers seem to surround the target, roll Wis DC 14 saving throw. On a fail, the target attacks with disadvantage.

Move (1 action). The doll moves up to its speed without provoking opportunity attacks.

Poisoned Porcelain Shards (2 actions). The doll throws out a volley of poison-tipped porcelain shards. Each creature within a 15' cone must make a Dexterity saving throw (DC 17). Those who fail take 6d6 piercing damage and must make a Constitution saving throw (DC 15). On a failure, a creature is poisoned until the end of its next turn.