Another monster I have been playing around with for a while. This one goes all the way back to my AD&D years, though under a different name. I have always liked the idea that Lichdom is never an assured thing for evil wizards and a lot can go wrong. Here is one of those times.
Dybbuk
Medium Undead (Incorporeal)
Frequency: Very Rare
Number Appearing: 1 (1)
Alignment: Chaotic (Chaotic Evil)
Movement: 180' (60') [18"]
Armor Class: 4 [15]
Hit Dice: 12d8+36*** (90 hp)
Attacks: 1 touch or by spells
Damage: 1d6+3 cold damage, or by spell (see below)
Special: Ethereal, incorporeal, harmed only by magic, possession, animate dead, undead
Size: Medium
Save: Magic-user 12
Morale: 10
Treasure Hoard Class: Special (dybbuk box)
XP: 3,500 (B/X, OSE) 3,600 (LL)
The process of becoming a lich is filled with peril and risk. Thankfully, for the forces of good, few learn the secret and fewer still meet with success. While most of the failed attempts to become a lich end with the permanent death of many evil mages, sometimes the process fails, the body is destroyed but the evil spirit lives on. These failed attempts at lichdom as known as a Dybbuk.
The dybbuk is the disembodied spirit of an evil magic-user who attempted to become a lich but whose body was destroyed before the final process was complete. The spirit remains tied to the mortal realms, unable to complete its transformation to a lich or move on to whatever plane it was due to move on too in the afterlife. The creature is evil and has a hatred for all living things.
A dybbuk is an incorporeal creature inhabiting the ethereal plane. It is invisible and can only be hit by magical weapons that can attack ethereal creatures. The creature will appear like a spectre and can be mistaken for one. When it chooses to attack a creature it will reenter the material world and become visible to all.
The most feared attack of the dybbuk is its ability to possess others. They will seek out magic-users and their pride demands that they seek out only the ones of the highest levels to possess. The victim must make a saving throw vs. spells (Lawful victims have a +1 to saves, Chaotic victims have a -1 to saves) or become possessed by the dybbuk. If possessed the victim gets another save every 24 hours. However, there is a progressive -1 each day to the save. Additionally, the victim will lose 1 point of constitution each day. When they reach 0 they are dead and cannot be resurrected as the dybbuk has destroyed their body and soul. If a victim makes the save the dybbuk cannot make another attempt for 24 hours.
Once in the body of a magic-user, the dybbuk will use any spells their host body knows. Typically they will attack anyone and everyone nearby, such is their hate for all living things. Those that can see ethereal creatures will see the dybbuk “riding” on the back of the possessed victim. A dybbuk also has the ability to animate 3d6 HD worth of skeletons and/or zombies. The bodies must be readily available, but a dybbuk will make sure plenty are on hand near it’s lair. These undead creatures follow the orders of the dybbuk til they are destroyed.
The dybbuk can be turned by a cleric as if it were a lich. Once in a victim though only an Exocism, Holy Word, Cleanse or similar spells will be effective in driving the evil spirit out. When the dybbuk is forced out it will spend the next 24 hours in its Dybbuk Box, or where its soul now resides. To fully destroy a dybbuk this housing for their soul must be destroyed.