FAMILIAR SPIRIT

According to the Bible, sorcerers or necromancers, who claimed the ability to contact the dead were said to have a "familiar spirit."  Familiar spirits are supernatural beings presumed, agreeably to a very old belief (Lev. xix. 31), to attend magicians or sorcerers, and to be at their beck and call on any emergency.

The word "familiar" in this usage is derived from the Latin word familiaris, meaning a "household servant," and was intended to imply that they had spirits as their servants, ready to obey their commands, which for some of them may have been partly true - but the spirits were demons.

Familiars were mentioned in Shakespeare's Macbeth, as the witches called their familiars. Many other works have utilized familiars. The most common species identified as familiars are cats, particularly black cats, owls, dogs, and sometimes frogs or toads. In later cases, familiars moved to more ethereal forms, often taking the shape of a "black man" thought to be representative of Satan.