Monster Almanac
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Underground Monsters

Browse D&D 5e monsters commonly associated with the Underground environment. This index is built directly from active monsters in the database, so new creature links appear here automatically when their environment tags are added.

Found 109 monsters
Active environments 43
Database loaded 1028 active monsters

Explore all environments

These links are generated from active monster relationships, not a hardcoded menu list.

Abyss12Arctic45Arena1Astral6Astral Sea16Battlefield1Carnival1Cave10Coastal93Desert74Divine Realm11Dream Realm3Dungeon370Extraplanar262Farmland1Feywild39Forest164Giant Holds1Grassland55Graveyard4Hell1Hill41Jungle36Laboratory3Mountain155Nine Hells18Ocean15Plains5Ravnica2River5Road6Ruins295Sewer1Shadowfell17Swamp91Temple17Tomb1Underdark136Underground109Underwater48Urban256Village1Wilderness137

Matching creatures

Pick a monster to open its full Monster Almanac entry.

Acid AntMonstrosityCR 1/4Open monster →AdhererAberrationCR 2Open monster →Adult Cave DragonDragonCR 16Open monster →Adult KruthikMonstrosityCR 2Open monster →Adult OblexOozeCR 5Open monster →Adult Rime WormMonstrosityCR 17Open monster →AlhoonAberrationCR 10Open monster →Amber OozeOozeCR 5Open monster →Amethyst Dragon (Wyrmling)DragonCR 4Open monster →Amethyst Dragon (Young)DragonCR 9Open monster →Amethyst GreatwyrmDragonCR 26Open monster →AurumvoraxMonstrosityCR 2Open monster →Aurumvorax Den LeaderMonstrosityCR 4Open monster →BanderhobbMonstrosityCR 5Open monster →BarghestFiendCR 4Open monster →BelashyrraAberrationCR 22Open monster →BlindheimHumanoidCR 2Open monster →Bone SwarmUndeadCR 6Open monster →BoneclawUndeadCR 12Open monster →Cave FisherMonstrosityCR 3Open monster →ChokerAberrationCR 1Open monster →ChuulAberrationCR 4Open monster →Core Spawn CrawlerAberrationCR 1Open monster →Core Spawn EmissaryAberrationCR 6Open monster →Core Spawn SeerAberrationCR 13Open monster →Core Spawn WormAberrationCR 15Open monster →Cranium RatAberrationCR 0Open monster →Dark CreeperHumanoidCR 1Open monster →DarklingFeyCR 1/2Open monster →Darkling ElderFeyCR 2Open monster →Death KissAberrationCR 10Open monster →DeathlockUndeadCR 4Open monster →Deep RothéBeastCR 1/4Open monster →Deep TrollMonstrosityCR 9Open monster →DerroHumanoidCR 1Open monster →Derro SavantHumanoidCR 3Open monster →DevourerUndeadCR 13Open monster →Dire AnglerfishMonstrosityCR 6Open monster →DissimortuumAberrationCR 10Open monster →DogmoleMonstrosityCR 2Open monster →DolgauntAberrationCR 3Open monster →DolgrimAberrationCR 1Open monster →DoombatMonstrosityCR 1Open monster →DraeglothFiendCR 7Open monster →Dragon EelDragonCR 8Open monster →Dragonblood OozeOozeCR 5Open monster →Duergar DespotHumanoidCR 12Open monster →Duskdale WurmMonstrosityCR 13Open monster →Earth DrakeDragonCR 6Open monster →EcorcheUndeadCR 5Open monster →Egg Hunter HatchlingMonstrosityCR 2Open monster →Elder OblexOozeCR 10Open monster →EntomberUndeadCR 6Open monster →Flail SnailElementalCR 3Open monster →Flesh ReaverAberrationCR 7Open monster →Fungal DrakeDragonCR 4Open monster →Gargantuan AntMonstrosityCR 11Open monster →GauthAberrationCR 6Open monster →Giant Ant LionMonstrosityCR 4Open monster →Giant JellyfishMonstrosityCR 3Open monster →Giant SlugMonstrosityCR 4Open monster →Githzerai AnarchHumanoidCR 16Open monster →Grell PsychicAberrationCR 4Open monster →Hoard ScarabMonstrosityCR 1/8Open monster →HollyphantCelestialCR 5Open monster →Ice ToadMonstrosityCR 3Open monster →Ki-rinCelestialCR 12Open monster →Kruthik AdultMonstrosityCR 2Open monster →Kruthik Hive LordMonstrosityCR 5Open monster →Kruthik YoungMonstrosityCR 1/8Open monster →MeenlockFeyCR 2Open monster →MerrenolothFiendCR 3Open monster →Mind Flayer ArcanistAberrationCR 8Open monster →Necrotic SlimeOozeCR 4Open monster →Neo-OtyughAberrationCR 7Open monster →Neogi SlaverAberrationCR 2Open monster →NeothelidAberrationCR 13Open monster →NosferatuUndeadCR 8Open monster →Oblex SpawnOozeCR 1/4Open monster →OgrepedeMonstrosityCR 6Open monster →Olive SlimeOozeCR 2Open monster →One-Eyed ShiverAberrationCR 5Open monster →Ooze MasterOozeCR 9Open monster →Orb WraithUndeadCR 7Open monster →PechHumanoidCR 1Open monster →Phantom FungusPlantCR 2Open monster →Prismatic RoperMonstrosityCR 8Open monster →Psionic OozeOozeCR 6Open monster →PsurlonAberrationCR 5Open monster →Pygmy TrollMonstrosityCR 3Open monster →QorgethAberrationCR 7Open monster →Remorhaz SpawnMonstrosityCR 5Open monster →RetrieverConstructCR 14Open monster →Rock RoachMonstrosityCR 1Open monster →Ruby OozeOozeCR 3Open monster →Sapphire Dragon (Greatwyrm)DragonCR 26Open monster →Sapphire JellyOozeCR 5Open monster →ScorpionfolkHumanoidCR 3Open monster →Sepulchral GuardianConstructCR 7Open monster →Shadow OozeOozeCR 4Open monster →Shadow SkeletonUndeadCR 2Open monster →Sharkjaw SkeletonUndeadCR 3Open monster →Skeletal JuggernautUndeadCR 5Open monster →Skull LordUndeadCR 15Open monster →Spawn of KyussUndeadCR 5Open monster →Star Spawn ManglerAberrationCR 5Open monster →Swarm of Cranium RatsAberrationCR 5Open monster →Topaz Dragon (Greatwyrm)DragonCR 26Open monster →Vampiric Mind FlayerUndeadCR 5Open monster →

What this page helps you do

Browsing monsters by environment is useful when you want threats that feel grounded in a location instead of chosen in isolation. This page narrows the bestiary to creatures that naturally fit the Underground environment.

The Underground environment currently shows 109 monsters in Monster Almanac, while the active taxonomy currently contains 43 environment pages.

Why browse by environment?

  • Find monsters that make sense in a specific location.
  • Match creature choice to the mood of the scene.
  • Reduce prep time by narrowing the full bestiary.
  • Build encounters that feel more natural and immersive.

Using Underground monsters in play

Once you choose a creature from this environment, decide how it appears in the world. A monster can act as a wandering threat, guardian, apex predator, local rumor, territorial danger, or part of a larger encounter chain.

This makes environment browsing useful not only for selection, but also for shaping tone, pacing, and atmosphere across the rest of the session.

Quick scene-building ideas

  • Use the environment itself to explain why the monster is here.
  • Pair the creature with fitting terrain and visibility conditions.
  • Add an NPC guide, survivor, hunter, or local witness.
  • Use CR differences to scale the danger level of the area.