Ghosts, Skeletons, and Zombies

I really like that you can encounter things like "a skeleton of a kobold" or "a zombie of a tourist". It's really entertaining. However, I just encountered the ghost of a mistress warlady on GC2, who promptly delimbed and beheaded me before I had much of a chance to react.

I'm wondering what sort of relations there are between the former monster and it's undead counterpart, and what spawn conditions/controls are set for them. Obviously I should never encounter a real mistress (let alone mistress warlady) on GC2 outside of wizmode or a mid/late game return to New Attnam. The fact that this one showed up - in ghost form, but still extremely dangerous - makes me wonder however...

(Note: this was in 507.)

Yup it's a known issue that needs to be fixed. Did the ghost of the mistress warlady have all her limbs attached?

That gives me an idea for an optional dungeon actually.

Very short, little loot. Full of invisible ghosts who won't immediately attack you, but if you happen to run into one it immediately turns hostile. At the end is an item that lets you see ghosts (perhaps just an amulet of ESP), or maybe a way to turn ghosts off for the rest of the game. Why? There's ghost versions of half the monsters in the game, gives other things a change to spawn.

Or perhaps a wand (or more) of "Etherealification", which would, when zapped, turn a creature into a ghost form of itself (most likely permanently, but this could be temporary), henceforth dropping all of its loot. This would, obviously, have no effect on boss monsters, and would perhaps have only 1 (maybe 2) uses per charge (depending on the amount given). The use would be twofold: You would be much more likely to kill a monster in its ghost form, and then its loot would simply be yours for the taking.