Pourquoi story
Narrative that explains why something is the way it is, generally fabulous or mythical / From Wikipedia, the free encyclopedia
A pourquoi story (French pronunciation: [puʁ.kwa] ⓘ; "pourquoi" meaning "why" in French), also known as an origin story, pourquoi tale or an etiological tale, is a fictional narrative that explains why something is the way it is, for example why snakes have no legs or why tigers have striped coats. Many legends, origin myths and folk tales are pourquoi stories.[1][2] A more pejorative term for these stories is a just-so story, coined by English writer Rudyard Kipling in 1902.