Ages ago, there was a war between mythic titans and the new gods of the mortal races. The gods won, and stripped power from most of the titans. One of the titans that fought was a female necromancer. She died pregnant, but centuries later,an undead thing crawled from her partially eaten body.
It wouldn't be a full-bore atropal, as those are full-on stillborn gods, but very similar, with necromantic powers. A city rose up by the lake where the titan fell, and was a great trade center for even a century or so, until this thing rose up. Now, it's a lost city, buried in jungle - but crawling with undead.
The atropal-like thing should be CR 20ish. I may have to stat it out myself, but before I do,what's the closest anybody knows of? Re-fluffing, after all, is easy.
