Lesser Star Spawn Emissary

Lesser Star Spawn Emissary CR: 19

Medium aberration, neutral evil

Armor Class: 19 (natural armour)

Hit Points: 241 21d8+147

Speed: 40 ft , fly: 40 ft , can hover

STR

21 +5

DEX

18 +4

CON

24 +7

INT

25 +7

WIS

20 +5

CHA

23 +6

Saving Throws: Int +13, Wis +11, Cha +12

Skills: Arcana +19, Deception +18, Perception +11

Damage Resistances: Acid, Force, Necrotic, Psychic

Condition Immunities: Charmed, Frightened

Senses: Truesight 120 ft, passive Perception 21

Languages: All, Telepathy 1,000 ft

Challenge Rating: 19

Aberrant Rejuvenation. When the emissary drops to 0 hit points, it's body melts away. A greater star spawn emissary instantly appears in an unoccupied space within 60 feet of where the lesser emissary disappeared. The greater emissary uses the lesser emissary's initiative turn.
Legendary Resistance (3/Day). If the emissary fails a saving throw, it can choose to succeed instead.
Unusual Nature. The emissary doesn't require any air, food, drink, or sleep.

Actions

Multiattack. The emissary makes three attacks.
Lashing Maw. Melee Weapon Attack +11 to hit, reach 15 ft, one target. Hit 16 2d10+5 piercing damage plus 13 3d8 acid damage.
Psychic Orb. Ranged Spell Attack +11 to hit, range 120 ft, one target. Hit 18 2d10+7 psychic damage.
Change Shape. The emissary polymorphs in to a Small or Medium creature of it's choice or back into it's true form. It's statistics, other than it's size, are the same in each form. Any equipment it is wearing or carrying isn't transformed.

Legendary Actions

The emissary can make 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The emissary regains legendary actions at the start of it's turn.

• Psychic Orb. The emissary makes a psychic Orb attack.
• Teleportation Maw (Costs 2 Actions). The emissary teleports to an unoccupied space it can see 30 feet of it and can make a Lashing Maw attack.
• Psychic Lash (Costs 3 Actions). The emissary targets a creature it can see within 30 feet of it and psychically lashes at that creature's mind. The target must succeed on a DC Wisdom saving throw or take 36 8d8 psychic damage and be stunned until the start of it's next turn.

Star Spawn Emissaries are the fingers of alien dimensions or entities. Only one is usually sent to any world at a time. They are mutable creatures taking on a form to fit into a society without revealing it's purpose. This purpose is to prepare the world for the coming of a star god and the emissary will do all it can to prepare for it's master's coming. Whether setting up cults, bring down other cults / religions, destroying governments in local regions, or working behind the scenes to change the land & opening a portal are just some of the potential objectives it will look to achieve. It is mutable enough to appear as any person, or even creature, to pass through a region unknown to all but maybe a select few if anyone.
What makes it so dangerous is if the emissary is killed, or completes everything necessary to achieve it's goals. At either point, it morphs into a Greater Star Spawn Emissary. At this point the only way to prevent either is to kill the greater star spawn emissary, and if not, this latter form can transform back into the lesser form after a long rest.
Should it reveal it's true form, an emissary appears as a roughly bipedal mass of agitated organs, self-cannibalising orifaces, and appendages suggestive of forms it has previously assumed.

Suggested Environments

Any, though usually in or around large settlements, or regions steeped in magic.

Related Organizations

• The Church Under The Sea