The Dybbuk is a type of malicious ghost hailing from Jewish folklore. The word dybbuk itself is derived from the ancient Hebrew language, meaning "to cleave to" or "to stick to." According to Jewish tradition, there are some souls so evil or that have committed such grievous sins during their life that they are unable to enter Heaven or Hell upon death. Instead, demons torment the spirits by with flaming whips and force these damned souls to wander endlessly all over the earth. Sometimes, these evil souls manage to temporarily escape their tormentors. Dybbuk are predominantly male, but they prefer to possess young women.
The Dybbuk is said to be able to possess any living or inanimate object. Although the spirit can possess animals, it prefers human hosts. Dybbuk possession may prove to be too much for the unfortunate animal, which may die of "natural causes" or a frantic attemp to drive out the invading spirit shortly afterwards. When the Dybbuk possesses a human, it absolutely refuses to leave. This person may be a total stranger, merely the best and the most convenient host the spirit could find. Legends tell of these spirits inhabiting horses and then jumping into the stable boy.
However, the Dybbuk can be exorcised. Certain magical or biblical verses may force the spirit to leave, but it is of the utmost importance that the Dybbuk be cooperative, or the host may possibly be hurt, perhaps even fatally. A rabbi experienced in this sort of exorcism must be found, who then must come to an agreement with the spirit. This may simply be a shortened duration of stay with the demons or an expiation of crimes and sins that will enable to possessing spirit to enter Heaven or Hell. However, if the exorcism isn't done in the right way, the host may be harmed or killed. If successful, the Dybbuk will be forced to evacuate the body from under the nail of the big toe, as this is where the least amount of damage will be caused to the host.
Some Dybbuk remain silent in their hosts, usually without being detected for a long period of time. The host may act out of character at times, but in general the spirit tries its hardest to be quiet and remain secretive. Some are more forceful in asserting their presence: speaking from the host's mouth, speaking in languages unknown to the host, possessing knowledge that the host shouldn't even know, or even speaking in an entirely different voice. Some are arrogant, usually making demands and claiming that they can't be forced to leave. The most powerful of Dybbuks may require several exorcists, and more than one exorcism may be required to cast out the possessing spirit.