Mi-Go Dimension Walker

Family: Mi-Go

This hideous crustaceous creature possesses multiple jointed limbs extending from its carapace and folded, fanlike wings. Its head is a brainy protuberance covered with tiny bristles that constantly cycle through a nauseating array of clashing colors.

Medium plant, neutral evil

Armor Class 15 (20 with shield)

Hit Points 212 (25d8 + 100)

Speed 30 ft., fly 20 ft.

18 (+4) 21 (+5) 18 (+4) 25 (+7) 18 (+4) 15 (+2)

Saving Throws Int +12, Wis +9, Cha +7

Skills Arcana +12, Deception +7, Medicine +9, Stealth +10, Yog-Sothothery +9

Damage Resistances fire; bludgeoning, piercing, and slashing damage from nonmagical attacks

Damage Immunities cold

Senses blindsight 30 ft., darkvision 60 ft., passive Perception 14

Languages Mi-Go, any seven other languages

Challenge 14 (11,500 XP)

Special Traits

  • Basic Star Travel. The mi-go can fly through space at great speeds. Travel times vary, but it can generally arrive within the same solar system in 3d20 months, or to another star system within 3d20 years.
  • Maddening Hyphae (Recharge 5-6). When the mi-go inflicts sneak attack damage on a foe, it can extend swiftly stinging filaments of fungal matter from its body to infect the wound. The target must succeed on a DC 17 Wisdom saving throw or become confused (as per the confusion spell) as the spores injected by the filaments spread through the victim’s nervous system. The target may attempt this Wisdom save at the end of each of its turns to end the confusion. This effect lasts until the target succeeds on this saving throw, to a maximum of 1 minute.
  • Sneak Attack (1/turn). The mi-go deals an extra 7 (2d6) damage when it hits a target with a weapon attack if it had advantage on the attack roll, or when the target is within 5 feet of an ally of the mi-go that isn’t incapacitated, and the migo didn’t have disadvantage on the attack roll. Its evisceration attack automatically deals this damage (included below).
  • Spellcasting. The dimension walker is a 14th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). It has the following wizard spells prepared.
    • Cantrips (at will): acid splash, chill touch, mending, minor illusion, prestidigitation
    • 1st level (4 slots): charm person, detect magic, fog cloud, shield
    • 2nd level (3 slots): mirror image, see invisibility, suggestion
    • 3rd level (3 slots): dispel magic, slow, vampiric touch
    • 4th level (3 slots): banishment, dimension door, fire shield, ice storm
    • 5th level (2 slots): cloudkill, seeming, teleportation circle, transport to Yondo
    • 6th level (1 slot): wave of oblivion
    • 7th level (1 slot): plane shift, project image
  • Unbreathing. The mi-go doesn’t need to breathe.


  • Multiattack. The dimension walker either makes two attacks with its pincers or casts three cantrips.
  • Pincer. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 10 (2d4 + 5) bludgeoning damage and the creature must succeed on a DC 18 Dexterity saving throw or be grappled (escape DC 14).
  • Evisceration. Melee Weapon Attack: +10 to hit, reach 5 ft., one target creature grappled by the mi-go. Hit: 30 (4d8 + 5 + 2d6) slashing damage and one of the target’s ability scores of the dimension walker’s choice is reduced by 1d4 until it finishes a long rest. If the target’s ability score is reduced to 0, it dies and the mi-go can extract the target’s brain intact.


Mi-go, commonly called the fungi from Yuggoth, are mainly fungoid in nature, but externally they have many features in common with crustaceans, such as multiple jointed limbs and a carapace. Folded against their bodies when not in use, their fan-like wings allow them to fly rapidly through space or clumsily in an atmosphere, and their heads are brain-like excrescences covered with small bristles which can change color for communication.

Mi-go develop custom spores and fruiting bodies, thus giving rise to endless varieties of their species. There are some mi-go whose hyphae grasp and feed from the very universe and the void of space itself, though most use these filaments to feed on animals and minerals. Their hyphae can sting and induce madness as they eat prey.

Most mi-go modify themselves surgically, magically, and genetically. Some are little more than gigantic brains while others are heavily-armored mi-go warriors. Adventurers typically encounter mi-go scouts, who are by no means the most advanced of their kind.

Masters of Technology. These highly intelligent creatures have advanced knowledge and skill in chemical and biological processes. Their brain cylinders and sensory machines are common examples of the many wonders they can create. As such, it is difficult to prepare for and know what to expect when encountering the mi-go. One could wield a new weapon a mi-go scientist developed to kill a specific person, which it does with unnerving efficiency. Another could spread madness-inducing spores modeled after the mi-go’s own hyphae.

Section 15: Copyright Notice

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

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