The bogeyman is a mythical creature used by adults to frighten children into good behaviour. Bogeymen have no specific appearances and conceptions vary drastically by household and culture, but they are most commonly depicted as masculine or androgynous monsters that punish children for misbehaviour. The bogeyman, and conceptually similar monsters can be found in many cultures around the world. Bogeymen may target a specific act or general misbehaviour, depending on the purpose of invoking the figure, often on the basis of a warning from an authority figure to a child. The term is sometimes used as a non-specific personification of, or metonym for, terror, and sometimes the Devil.

A monster is a type of fictional creature found in horror, fantasy, science fiction, folklore, mythology and religion. Monsters are very often depicted as dangerous and aggressive, with a strange or grotesque appearance that causes terror and fear, often in humans. Monsters usually resemble bizarre, deformed, otherworldly and/or mutated animals or entirely unique creatures of varying sizes, but may also take a human form, such as mutants, ghosts, spirits, zombies, or cannibals, among other things. They may or may not have supernatural powers, but are usually capable of killing or causing some form of destruction, threatening the social or moral order of the human world in the process.