A moroi is a type of vampire Romanian folklore. A female moroi is called a moroaică. In some versions, a moroi can be called a phantom of a dead person of which leaves the grave to draw energy from the living. Some would even consider this to be psychic vampire since psychic vampires feed from others energy.
Moroi are often associated with other figures in Romanian folklore, such as strigoi, which is another type of vampire. As with most concepts in folklore, the exact characteristics prescribed to moroi are various from source to source. It has been reported that the child of a woman impregnated by a nosferat (a sort of incubus-vampire and also the name of Nosferatu) would be extremely ugly and covered with very thick hair, very quickly becoming a moroi.
They are also sometimes referred to in modern stories as the living offspring of two strigoi. It may also signify an infant who died before being baptized. However, the origins of the term "moroi" are unclear, but it is thought by the Romanians to have possibly originated from the Old Slavanicword mora (meaning nightmare).
Moroi can also be forms of demons which possess a living body, usually the body of an animal or another human. Moroi can be put under the control of a strigoi.
In conclussion, I do NOT take on the form of others nor do I take on the form of a demon.