Yallery Brown is a mischievous fairy

Fairy

A fairy is a type of mythical being or legendary creature, a form of spirit, often described as metaphysical, supernatural or preternatural.Fairies resemble various beings of other mythologies, though even folklore that uses the term...

-like nature spirit

Animism

Animism refers to the belief that non-human entities are spiritual beings, or at least embody some kind of life-principle....

 in an old Lincolnshire

Lincolnshire

Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...

 folk tale

Folklore

Folklore consists of legends, music, oral history, proverbs, jokes, popular beliefs, fairy tales and customs that are the traditions of a culture, subculture, or group. It is also the set of practices through which those expressive genres are shared. The study of folklore is sometimes called...

 from England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, which itself is usually named after the creature.
According to Joseph Jacob's version of the story, a young lad named Tom was sitting in a field resting during his daily labours when he heard a little whimper, like the sound of a young child in distress. Upon further investigation Tom found a little creature trapped under a flat stone.