Posted a small update - I added a few new creatures that aren't layer-specific, so they can appear in all layers.
This is mostly to make the encounters with some of the deadlier, layer-specific creatures more uncommon - some of them were rather nasty to fight against, so hopefully this should make them not as common as they once were.
There's 3 predatory creatures added in total, and 6 non-hostile ones.
Predators:
Blind Screecher - human-sized, intelligent bat-like humanoids with no eyes. They appear in groups, but are quite cowardly and run away at very early signs of opposition. They can shriek, which has a chance of causing minor dizziness. Their bites also suck out blood, however they aren't actively vampiric. They are also playable in adventure mode.
Deep Stalker - lizard-like creatures. They have stingers at the ends of their tails, and can become invisible when fleeing. Can be war/hunting trained.
Cave Pygmy - hairless humanoids, smaller than even kobolds - they appear in groups of 5 to 8, and may attempt to steal food or items, and will also drink booze and pull levers. Very cowardly.
Non-hostile:
Cave Hound - one-eyed, hairless quadrupeds - same size as a human. Scavengers, but can be war/hunting trained. They are the uncorrupted form of Bloodmongrels.
Shaggy Molebull - large quadrupeds, a cross between a bull and a mole. It has a pair of horns, and a shaggy coat - can be sheared off.
Crystalline Charger - goat-like creatures, with crystalline horns. They can be war/hunting trained, and can be milked - their milk grants magic immunity.
Gloomwing - small fliers that look like bats with a mosquito-like proboscis, and large compound eyes. They hunt vermin when kept as pets.
Boulderskin - muscular bear-like quadrupeds. Their skin is quite a fair bit tougher than average - and so is the leather made from it. Can be war/hunting trained.
Darkdweller - humanoids with cephalopod-like heads. They are related to Nightmare Weavers and Flesh Harvesters - though unlike them, they still worship their primal gods of darkness, instead of worshipping eldritch deities. They can cast two buff spells - Dark Strength, which increases strength and toughness and prevents the affected from feeling pain, and Shadewalk, which increases agility and speed. They are playable in adventure mode.
Lastly, I added beneficial syndromes to some of the drinks brewed from underground plants - Slime Beer made from slime pods already had an increased disease resistance syndrome, but now shadewine (made from shadecones) increases agility, grave ale (brewed from corpseblooms) increases disease resistance, marrow juice (made from marrowplants) increases toughness, and hellwine (brewed from hellblood shrubs) increases strength. The buffs last quite a long time, but are only a flat point increase, rather than doubling the stat.
Thats all for now, I'm gonna keep working on the biome revamp - don't expect it too soon, since I still have quite a lot of work to do on it.