2) Thorn Fey: Take elves and give them some kind of plant template, like the Woodling. Add in a bit of Spiker, and you have Elves who are part Cactus.
3) Warforged: given their construction, they'd make ideal desert war constructs...and "clockwork" critters fit in with Ravenloft. An additional tweek- lift a page from Dr Who's Cybermen & Daleks- they're not actually constructs, but some kind of creation into which psionically active brains have been housed (make them natural psionics, drop a couple of their immunities).
4) Take some kind of corporeal undead like Wights or Ghouls and make them living critters. Transform their energy drain attacks into moisture drain attacks.
5) Horned Lizard Men/Kobolds. Add a special attack- "Squirt Blood from Eye" (Ex), works like a Daze cantrip, usable at will (requires a Fort save by PC for each use over 3). Reduce their natural claw/bite attacks to minimal, give them natural armor with spikes.