I saw something on X about horses being burned by foxes which is probably bs, the only thing I can find about the bakotsu is how it dies.
There's literally nothing on bokutsu on internet.
But I found something closer it though.
It's matches the most things except for being a horse 💀💀
Gashadokuro (餓者髑髏)
Gashadokuro means “starving skeletons” in Japanese. However, they are more accurately, huge starving skeletons. As in, immensely powerful bony Japanese monsters several times the size of an average human.
Believed to be formed from the bones of those who died in battle or famine, these horrible aberrations roam the wilderness hunting for victims while making gachi gachi sounds. At the sight of any, they seize and chomp off heads, or just crunch the hapless victims whole.
Because they are so large,
they are nigh indestructible too(reference venus representing Diamond). A popular belief is that a Gashadokuro will only crumble when the negative energy that created it is expended. Something that could take a long time to happen.