A mod that adds many new creature, vermin and plant types to the caverns, giving each of the three layers a different theme - and adding more difficulty and variety. This versions only contains the custom raws, without the alterations to vanilla underground plants.

In order to install, just extract the "raw" and "data" folders to the main DF directory.

Subterranean Paradise - Layer 1 Chasm
The simplest layer - it contains stranger relatives of aboveground animals, adapted to life underground. From the small, pack-hunting Spike Rats, to the tough Stone Boars and the massive Undertyrants, danger here takes many shapes and sizes.

Full list of predators.
Fungal Woods - Layer 1 Water
An underground woodland, full of towering fungus. Most of the living creatures here are ambulatory plant-life or fungal-based beings - the few unfortunate enough to die are converted into Moldspawn or Moldslaves by the Amanitarians.

Full list of predators.
Insectoid Hive - Layer 2 Chasm
Some of the deeper underground tunnels are the habitat of various types of insectoid beings. Few would head down there, fewer still live to tell the tale. The Hive Queens and Swarm Lords bide their time here, seeking to purge the caverns and eventually the surface world of all non-insectoid life.

Full list of predators.
Land of the Dead - Layer 2 Water
What little remains of once-sprawling underground empires can be found here, in the form of many unnaturally mutated zombies, howling spirits and feral skeletal beings - with several necrophagous beasts moving in, attracted by the scent of decay. The Lords of the Risen, extradimensional demigods, have turned these tunnels into their domain, warding off intruders with their undead minions.

Full list of predators.
Border of Hell - Layer 3 Chasm
The lowest tunnels are inhabited by many lesser demons and their commanders. Most of those unfortunate enough to encounter them are captured and turned into slaves - even their souls are not safe from being forced to serve - whereas the particularly hated enemies of the demons, such as the dragons, are simply mutilated, driven insane, and left alive to wander the caverns for eternity.

Full list of predators.
Dementia - Layer 3 Water
Something stirs deep below the earth...An unspeakable yet sickly horror whose mere presence is enough to warp the caverns into an organic, diseased dreamscape. Its minions kidnap those who dwell in the surface world, using their victims as material for creating horrid aberrations of flesh.

Full list of predators.