Yes, I know it doesn't kill them, but does it cripple their senses at all? Does a headless zombie or skeleton lose its Darkvision and go blind? Or are their senses independent of the head?
As far as I can tell by RAW it wouldn't effect them at all.
Others, such as golems and undead creatures other
than vampires, are not affected by the loss of their heads.
Personally I find that a bit daft so I houserule it that anything that would logically use the eyes and ears in it's head to see and hear would go blind and deaf from the effect, as well as lose their scent ability (if any) assuming they used their nose to do it. but what I'd do isn't supported by what's in the book.
By raw, no. They keep all their abilities.
That said, I also Don' t like that interpretation since corporeal undead can be crit now, it doesn't' make sense
I'd imagine they'd lose any bite attack they have...
That...is a damn good point.
I think I may rule that it stunts their sense a bit at the least. Takes away scent and limits sight to about half the distance they normally have, if not blinds them entirely (even if they're seeing with magic, losing a chunk of your body has t have SOME effect on that magic, no?)