Surface habitats
Lush (grassy, serene — includes lush/deciduous forest)
- Common: Hobgoblins, Orcs, Dire Wolves, Gnolls, Bugbears, Kobolds, Ogres, Spiders, Forest animals
- Uncommon: Blink Dog, Hippogriff, Grick, Hags, Owlbear, Ankheg, Displacer Beast, Ettin
- Dangerous: Revenant, Shambling Mound, Troll, Werebear
- Encounter Lush Surface Biome
Coastal (wet, near bodies of water)
- Common: Kobolds, Spiders, Sea Spawn, Sea Hag, Harpy, Giant Toad
- Uncommon: Merrow, Manticore, Tortle Druid, Sahuagin
- Dangerous: Giant Crocodile, Water Elemental, Cyclops Sentry, Hydra
- Encounter Coastal Surface Biome
Desert (arid, sandy)
- Common: Gnolls, Ogres, Wights, Mummies
- Uncommon: Sphinx of Wonder, Air Elemental, Giant Scorpion, Blue Dragon Wyrmling
- Dangerous: Fire Elemental, Efreeti, Tlincalli, Hobgoblin Warlord
- Encounter Desert Surface Biome
Snowy (cold, boreal — includes boreal/conifer forest)
- Common: Brown Bears, Polar Bears, Saber-Toothed Tiger, Gnolls, Ogres, Winter Wolf
- Uncommon: Yeti, Manticore, Polar Serpent, Winter Wolf
- Dangerous: Troll, Werebear, Mammoth, Frost Giant
- Encounter Snowy Surface Biome
Rocky (highland/mountain)
- Common: Brown Bear, Dire Wolf, Hippogriff, Ogres, Gnolls, Duergar
- Uncommon: Green Hag, Basilisk, Manticore, Chuul
- Dangerous: Air Elemental, Earth Elemental, Wereboar, Werebear, Troll, Hill Giant, Bulette, Ettin
- Encounter Rocky Surface Biome
The Underdark
Layer 1 - Caves
- Common: Small Spiders, Bats, Giant Rats, Kobolds
- Uncommon: Basilisks, Myoconids (isolated stragglers)
- Dangerous: Gray Ooze, Carrion Crawler, Darkmantle, Cave Fisher
- Encounter Underdark Layer 1 Caves
Layer 2 - Mushroom Caves
Layer 3 - Deep mushroom caves and grottoes
Layer 4 - Crystal cave layer
- Common: Spiders, Basilisks, Cave Fishers, Gelatinous Cubes
- Uncommon: Shadows, Gray Ooze
- Dangerous: Trolls (some showing signs of oripathy — crystal growth, failed regeneration), Chuul, Black Pudding, Water Weird
- Crystal Caverns; Originium is abundant and common in its active form here. General Underdark population.
- Old Magma Chambers / Volcanic Tunnels of the old civilization.
- Encounter Underdark Layer 4 Crystal Cave Layer