What exactly is a Soucouyant?
That is a very interesting question, and here's the answer: a soucouyant is a shape-shifting bloodsucking creature. At first the creature looks like an old woman (though in some legends, it doesn't have to just be an old woman), then she goes in her true form, a fireball, where she flies across the night sky in search of a victim. They come from entering the home from going through keyholes, cracks, and crevices.
They suck blood from people's arms, legs, while they sleep. By the way to become into a different form the soucouyant will strip its skin off and put it in mortar. Witches believe that the skin of these creatures work perfectly for their black magic. Speaking of witchcraft, the soucouyant practices black magic. What it does with the victim's blood is a disturbing thing according to its folklore, the soucouyant will trade its victims blood in order for 'evil' powers. They trade this blood to Bazil, a demon.
Many have heard of the legend of vampires and rice, well the folklore of the soucouyant, which is a vampire-like creature has a legend about rice also. To expose one of these creatures, a person can throw rice everywhere, which will obligated the creature to count every grain of rice. With that task, the soucouyant will be caught in the act, and the person will know that the so called human neighbor is actually a bloodsucking fireball.
Now to destroy such of a creature, one must put coarse salt in the mortar that contains the skin of the shape-shifting creature.
According to some of the folklore a soucouyant is in the class of spirits called jumbies. A jumbie is a demon or spirit that is in Caribbean folklore. The word jumbie can also be spelled, jumbee or mendo.
So a soucouyant is a relation to the vampire myth that is found in Caribbean folklore. Its true form is a vampire-like fireball that attacks its victims while they sleep.