Cthulhu Mythos Creature Reference
This page provides a quick reference for major Cthulhu Mythos creatures, organized by type and threat level. For complete stats and detailed information, consult the full bestiary resources or your game system's rulebooks.
🔗 Full Resources: For complete creature statistics and lore, visit the
Mythos Bestiary Resources page which links to official
references like the Malleus Monstrorum and Call of Cthulhu Wiki.
Creature Categories
Minor Threats
Can be encountered and possibly defeated by investigators
- Ghouls
- Serpent People
- Deep One Hybrids
- Rat-Things
Major Threats
Extremely dangerous - survival is often the best outcome
- Deep Ones
- Mi-Go
- Shoggoths
- Byakhee
Cosmic Entities
Beyond mortal comprehension - encountering one means certain doom
- Cthulhu
- Hastur
- Azathoth
- Yog-Sothoth
Common Mythos Creatures
| Creature | Threat Level | Typical SAN Loss | Description |
|---|---|---|---|
| Ghoul | Minor | 0/1d6 | Hunched, canine-like humanoids dwelling underground, feeding on corpses |
| Deep One | Major | 1/1d6 | Amphibious fish-frog humanoids serving Cthulhu and Dagon |
| Deep One Hybrid | Minor | 0/1d3 | Human-Deep One crossbreeds, gradually transforming |
| Mi-Go | Major | 1d2/1d6 | Fungoid crustaceans from Yuggoth (Pluto), highly technological |
| Shoggoth | Major | 1d6/1d20 | Massive protoplasmic entities, once enslaved by Elder Things |
| Byakhee | Major | 1d3/1d10 | Interstellar winged horrors serving Hastur |
| Star-Spawn of Cthulhu | Major | 1d6/1d20 | Octopoid servants resembling their master Cthulhu |
| Dark Young | Major | 1d8/1d20 | Massive tree-like beings with tentacles, spawn of Shub-Niggurath |
| Serpent People | Minor | 0/1d6 | Ancient reptilian race, masters of illusion and sorcery |
| Hunting Horror | Major | 1d6/1d10 | Serpentine flying horrors serving Nyarlathotep |
Great Old Ones & Outer Gods
⚠️ Warning: Encountering these entities typically means instant insanity or death.
They are campaign-ending threats meant to be feared, not fought.
| Entity | Type | SAN Loss | Domain |
|---|---|---|---|
| Cthulhu | Great Old One | 1d10/1d100 | High Priest of the Great Old Ones, sleeps in R'lyeh |
| Hastur | Great Old One | 1d10/1d100 | The Unspeakable One, associated with Carcosa and the King in Yellow |
| Nyarlathotep | Outer God | 1d10/1d100 | The Crawling Chaos, messenger of the Outer Gods, many forms |
| Azathoth | Outer God | 1d10/1d100 | The Blind Idiot God, nuclear chaos at center of universe |
| Yog-Sothoth | Outer God | 1d10/1d100 | The Key and the Gate, knows all of time and space |
| Shub-Niggurath | Outer God | 1d10/1d100 | The Black Goat of the Woods with a Thousand Young |
| Dagon & Hydra | Great Old Ones | 1d6/1d20 | Rulers of the Deep Ones, worshipped by undersea cults |
💡 Using Mythos Creatures in Your Game
For Keepers/GMs
- Minor threats can be defeated through cleverness
- Major threats require escape or banishment
- Great Old Ones should be glimpsed, not fought
- Build terror through anticipation and hints
- Most creatures work better as mystery than combat
- SAN loss triggers before physical danger
Encounter Design
- Show evidence of creature before revealing it
- Use servants/cultists as primary antagonists
- Create atmosphere through description
- Make creatures alien and incomprehensible
- Focus on cosmic insignificance of humanity
- Victory should feel pyrrhic at best