Demons

A demon is a malevolent supernatural entity. Historically, belief in demons, or stories about demons, occurs in religion, occultism, literature, fiction, mythology, and folklore; as well as in media such as comics, video games, movies, anime, and television series. Belief in demons probably goes back to the Paleolithic age, stemming from humanity's fear of the unknown, the strange and the horrific.
There are uncountable number of demons; nevertheless they maybe cathegorized. Also, they are organized in an hierarchical structure, some parts are genealogical.