A short selection from the physical books I have at the ready (I may delve through my PDFs and maybe other books later):
RangerWickett said:
Adventure 6 has lots of corporeal flaming undead, and will showcase the blood-animated skeleton of a gold dragon. Party level 11.
Tome of Horrors II has
- Cinder Ghoul (Large Undead, CE, CR 7, can take smoke form and can burn the inner organs of a victim)
- Fire Phantom (Medium Extraplanar Undead, CE, CR 5, can hurl small fire attacks and immolate itself; can't be turned).
Creature Collection II (3.0 source) has the Burned Ones (Medium Undead, no fire subtype, CE, CR 4 (may be higher in reality); also can immolate themselves). Creature Collection III has the Ashcloud (Large Undead, NE, CR 7, can engulf, smother and take cloud form)
RangerWickett said:
Adventure 7 has incorporeal undead, like a ghost dire wolf pack, as well as some demons that are complicated and really tied to the plot. Party level 13.
Chances are that any OGL monster book has one and/or the other of those types.
To not quite leave this empty, the
Slaughterwar Master is not incorporeal, but may fit in somewhere (not necessarily this adventure.
RangerWickett said:
Adventure 8 has winter-themed foes, and an underground fortress which I want to have be guarded by things other than just soldiers. Party level 15.
Not quite so easy to find many cold guys of appropriate CRs here, but most books have low-CR creatures that may fit the winter theme. If you're willing to go up to CR 18, Tome of Horrors II has the slorath, a Gargantuan serpent with a paralyzing gaze. CC Revised has the huror, a Huge CR 16 bear that is the center of a blizzard. CCII has the Tundra Lord, a mammoth that can deafen its foes and cause an earthquake spell, CR 9 (might need a few more HD, as written it has fewer than an elephant).
CCIII has
- Icewrack dragon, CR 12.
- Windigo, incorporeal outsider that can possess others, which even if driven out can turn the victim into a windigo as well.
Strange Lands - Lost Tribes of the Scarred Lands has a whole section of monsters for a frozen continent. (filling this in later)
RangerWickett said:
Adventure 9 is crazygonuts. If you have any ideas for cool monsters, throw them this way. Party level 17.
Shade, do you think there'd be room for the
Drenkari here?