Starspawn, Larval

Large aberration, chaotic evil

Armor Class 17 (natural armor)

Hit Points 161 (14d10 + 84)

Speed 40 ft., fly 50 ft., swim 30 ft.

24 (+7) 16 (+3) 22 (+6) 19 (+4) 20 (+5) 19 (+4)

Saving Throws Str +11, Con +10, Int +8, Wis +9, Cha +8

Skills Athletics +11, Yog-Sothothery +9

Damage Immunities cold, poison, psychic

Condition Immunities poisoned, prone

Senses blindsight 30 ft., darkvision 60 ft., passive Perception 15

Languages Aklo, telepathy 300 ft.

Challenge 12 (8,400 XP)

Special Traits

  • Body Control. The starspawn can contort, stretch, or compress its body to an extraordinary degree. This has the following effects: Amorphous. The starspawn can move through a space as narrow as 2 feet wide without squeezing.
  • Immovable. The starspawn has advantage on ability contests and saving throws against effects that would move it.
  • Prodigious Reach. As a bonus action, the starspawn can extend the reach of one of its weapon attacks by up to 300 feet until the start of its next turn.
  • Immortality. The starspawn doesn’t need to eat or breathe and doesn’t age.
  • Innate Spellcasting (Psionics). The starspawn’s spellcasting ability is Intelligence (spell save DC 16). It can innately cast the following spells, requiring no components:
    • At will: sending
    • 3/day each: dream, suggestion (can target creatures through dream)
    • 1/day: feeblemind
  • Regeneration. The larval starspawn regains 20 hit points at the start of its turn. If the starspawn is damaged by fire or by a weapon with an Elder Sign, this trait doesn’t function at the start of the starspawn’s next turn. The larval starspawn dies only if it starts its turn with 0 hit points and doesn’t regenerate.
  • Unfathomable Mind. A starspawn’s mind is overwhelming in its power and alien structure. When a creature initiates mental contact with a starspawn (including via telepathy) or attempts to learn the starspawn’s emotions or thoughts (even unsuccessfully), it learns no information except what the starspawn intentionally shares and it must make a DC 16 Intelligence saving throw. An aberration, celestial, elemental, fiend, or creature that has attempted this saving throw (successfully or not) against any starspawn’s Unfathomable Mind since the last dawn automatically succeeds. On a failed save, the creature that contacted the starspawn’s mind takes 26 (4d12) psychic damage and is stunned until the end of the starspawn’s next turn. The larval starspawn can use its Telepathic Assault action to use this trait offensively.


  • Multiattack. The larval starspawn can use its Frightful Presence. It then makes two with its claws and either attacks with its tentacles or uses its Telepathic Assault.
  • Claw. Melee Weapon Attack: +11 to hit, reach 20 ft., one target. Hit: 14 (2d6 + 7) slashing damage.
  • Tentacles. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 34 (6d8 + 7) bludgeoning damage and a medium or smaller target is grappled (escape DC 15). Until the grapple ends, the target is restrained. The starspawn has six tentacles, each of which can grapple one target.
  • Frightful Presence. Each creature of the larval starspawn’s choice that is within 60 feet of the larval starspawn and aware of it must succeed on a DC 16 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the starspawn’s Frightful Presence for the next 24 hours.
  • Telepathic Assault. The larval starspawn telepathically reveals unfathomable concepts to a target creature within 300 feet or that it is currently contacting via dream or sending. The target must make a saving throw against the starspawn’s Unfathomable Mind trait. In any case, even the smallest larval starspawn possesses a genius-level intellect by human standards, though this is difficult to measure due to the alien nature of their minds. They typically exist on different planes of existence simultaneously and obey different natural laws than those common to humanity.
  • Immortal. Starspawn are immortal and almost impossible to kill. When sealed away by magic or physical effects, they can sleep for centuries without difficulty.


Starspawn reproduce by budding or fission: a smaller larval starspawn simply drops off a large one. The smaller entity retains a good portion of the parent’s wisdom and knowledge, but has fewer or weaker spells and psionics available, as its lesser size means it has a more limited mental capacity.

Section 15: Copyright Notice

Sandy Petersen’s Cthulhu Mythos, © 2018, Petersen Games; Authors: Sandy Petersen, David N. Ross, James Jacobs, Arthur Petersen, Ian Starcher.