A being of anomalous or uncertain aspect or nature is called a creature.
A lower animal, such as a farm animal is often refered to as a creature.
The sleep of reason produces monsters.
An animal or plant that is abnormal in form is called a monster.
A malformation of a plant or animal is called a monstrosity.
Demons are evil spirits, and a source or agent of evil, harm, distress and ruin.
Supernatural beings of Greek mythology intermediate between gods and men are demons.
