ELI5: Explain Like I'm 5

Fictional disease

A fictional disease is a made-up disease that doesn't really exist. It is often used in books, movies, television shows, and video games as a way to make something more exciting or mysterious. It may have symptoms like a real illness, but it's not real and can't harm you. Sometimes authors use a fictional disease as a way to teach people about how a real disease works, or just as a way to make their stories more interesting.