I found a site with everything I need except the magma pool (I modded out aquifers, all non-sand soils, and made all stones except limestone, chalk, dolomite, granite, gabbro, diorite, and marble igneous extrusive).
Image of the dread reveal to come (forecast: pain)
EDIT:
The demons:
10 Haunts of Fire (An enormous
blob composed of flame. It has a round shell and it undulates rythmically. Beware its poisonous sting!)
31 Specters of Salt (A
nother huge
blob composed of salt. It has an enormous shell and it has a gaunt appearance.)
40 Gray Spirits (A gigantic hornet composed of ash. It has an enormous shell and it has a gaunt appearance. Beware its poisonous sting!)
12 Hadrosaurid Demons (A huge one-eyed
hadrosaurid. It has thin wings of stretched skin and it squirms and fidgets. Its crimson scales are jagged and close-set. Beware its deadly dust!)
10 Winged Demons (A gigantic scaly snail. It has thin wings of stretched skin and it belches and croaks. Its dark indigo scales are large and close-set. Beware its webs!)
10 Salt Brutes (a huge quadruped composed of solid salt. It has three narrow tails and it has a gaunt appearance. Beware its webs!)
43 Lavender Jade Brutes (A gigantic quadruped composed of lavender jade. It has a twisting, jointed trunk and it squirms and fidgets. Beware its deadly dust!)
156 demons total, 51 unkillable except by cave-in, obsidian, or new version (too warm for ice).
The undead:
32 One-Humped Camels (16 zombie, 16 skeletal)
17 Foxes (7 zombie, 10 skeletal)
36 Muskoxen (19 zombie, 17 skeletal)
18 Zombie Green Devourers
93 Gazelles (55 zombie, 38 skeletal) + 1 zombie, 1 skeletal dead
196 undead total (115 zombie, 81 skeletal)
Shall I proceed? I'm going to wait for 31.09...