What are living Terrorgheists like?

[Arnizipal]

I love the model of the Terrorgheist, but its inclusion in the Vampire Counts army years ago did pose me with a problem as a person who appreciates background: what does a living version of this creature look like, and where does it come from?
Exisiting background says it's a bat the size of a dragon that lived off caravans and pegasi.
But where would a bat of that size even live in Sylvania? And are there even enough of them to reliably field them in armies?

Am I thinking about this too hard?

[Lord Damocles]

Sylvania borders the Worlds Edge Mountains, so maybe they live there? With all the pegasi..?

Or maybe Sylvanian castles have really big eaves, and the giant bats live in there.

[Arnizipal]

The World Edge Mountains are a valid suggestion. Seem to be filled with various monsters depending on which army you play
But why would they only live there? And why have they all died out?

I have no problem with something new being added and everyone acting like they have always been there (Demigryph cavalry come to mind) but out of all the new stuff that was added to Vampire Counts, this one I found the hardest to rationalize.

[Ultimate Life Form]

Of course this is all just speculation and I'd wager no one at GW ever gave this a second thought, but the answer to "why does x and y only live in one place" is usually because they have been hunted to extinction elsewhere, either by Lizardmen or later humans, ogres and such. A Terrorgheist doesn't seem to be a very nice critter to have around so they were probably exterminated, like wolves and bears in the real world. The Empire and Dwarves don't like their caravans eaten. Before the coming of Sigmar the Empire rightfully belonged to the Beastmen and Gilles le Breton kept himself busy ridding Bretonnia of the Orcs who dwelled there.

Keep in mind we are supposed to believe that the Warhammer world is chock-full with all kinds of surreal monsters and stuff and the various creatures we see employed in the armies really only scratch the surface. Just have a look at the Monstrous Arcanum to see what kinds of wierd beasties lurk in the deeper recesses of the background. If there's a problem with such trivial stuff as the fundamental laws of the universe then Chaos did it. It's an excuse for GW to throw at us whatever they like.

[Arnizipal]

Hunted to extinction. Simple yet elegant.
Thanks