Monster is a term for any number of mythical beasts that frequently appear in mythology, legend, and horror fiction. They are also a mainstay of Dungeons & Dragons and similar role-playing games. "Monster" usually, but not always, implies that these creatures are larger than human size. It almost always implies that the creatures are powerful and hostile to the hero, and must be overcome to succeed in the quest.
... it merely designated anyone who assumed power for any period of time without a legitimate basis of authority.
The first to have the title of "Tyrant" was Pisistratus ...