This is an amazing sounding mod. I’ll have to give it a test run ASAP.
As for some suggestions I have:
I know that the mere mention of it puts some dwarves in shock, but what about another big scorpion creature? Specifically, I’m talking about the Girtabilu.
Girtabilu are what you get when someone says: “Hey, you know what would make centaurs better? Scorpion lower Half instead of a Horse!”
They would be a Desert/Wasteland response to Centaurs, [assuming centaurs only appear in Shrubland/Plains]. Firing off arrows coated in it's own venom at range, an being able to rend and pierce with claw and tail up close.
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Another that comes to mind would be the Lindwurm/Linnorm. They are large dragons, though they more fit the title of ‘Wurm’. They are serpentine, generally with no wings, and either no limbs, or one set of frontal limbs. Famous examples of Lindwurms would be Fafnir, Nidhogg, and Jormungander. Based on their lands of origin, (mostly the Nordics), they would mostly live in more frigid and icy biomes.
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And hey, how about to tie these two concepts together with a nice pretty bow, a Megabeast idea. From Zoroastrian mythology, the creature that brings about the apocalypse is Azhi Dahaka, or Zahhak. A three headed Dragon with insects that crawl over its body, and in some versions, get this:
IT BLEEDS SCORPIONS!! It would work likely in a similar manner to Meph's idea on the Monkey king, just instead of copies of itself, it would turn its severed parts/blood into scorpions. So if you manage to pop some arrows into it, but don't kill it and allow it to wander and bleed, you'll soon be swarming in scorpions. I've no idea if this is possible with blood, but just the thought of it sounds so awesome to me.