The white text in Cleon's post 1135 looks good to me. Just flavor/tactics left?
I've been thinking, since this creature is formed from unburied bones maybe it should have Rejuvenation like a ghost but a bit less potent, so if you "kill" a Cackling Bones it might reform from its remains on the anniversary of its (original) death?
I'm not opposed to the idea, but it does seem to be getting rather lenghty for a low-CR critter.
What, don't low level critters deserve as much love as high level ones?
I don't know that I'd find it so lengthy, but these don't strike me as particularly good rejuvenation candidates based on that fluff text. I mean, the bit about being unburied applies to all kinds of undead that don't have it.