This question is based on General Literary Principles.
A work which takes place in a non-existent world or which concerns an incredible character is
Answer Details
A work which takes place in a non-existent world or concerns an incredible character is called a "fantasy". The term "fantasy" is used to describe literature that involves magic, mythical creatures, supernatural powers, and other elements that are not found in the real world. Fantasy is often set in an imaginary world with its own rules and laws, and may involve epic quests, battles between good and evil, and the triumph of the hero over seemingly insurmountable obstacles.