After a moon fox dies, as long as one tail is chopped off, its body will immediately turn to smoke and return to the embrace of the Moon Goddess. Of course, there is also the possibility of trying to exploit a bug by chopping off all its tails at once, but that would result in none of them staying behind.
The situations with the moon fox's tails were experiments done by Blue Star players from a past life who tried to make moon fox tails into a scarf. However, the first tail of the moon fox is not completely impossible to handle. Rita thought of a workaround: players with telepathic abilities could interrogate a moon fox. It would be tedious, though.
But the most troublesome items were the Candlebeast's flame tail and the Undead Spring drop from a death's heart.