A monster is any fictional dangerous or hideous creature, usually in legend or horror fiction. The word “monster” derives from Latin monstrum, an aberrant occurrence, usually biological, that was taken as a sign that something was wrong within the natural order.

The word connotes something wrong or evil; a monster is generally morally objectionable, physically or psychologically hideous, and/or a freak of nature. It can also be applied figuratively to a person with similar characteristics.

Here is a collection of monsters from Japanese mythology.