The cavelings are basically mutants and most of them aren't much cop in a fight, as I recall, so you may as well just use some sort of generic humanoid stat block (perhaps human, since I think they tend to be human in origin). If you can find any product that has mutations in (I know of Chaositech but there are sure to be others, perhaps free web stuff) you can add a few of those in or just fudge it, if it's just for personal use so to speak.