Sredni Vashtar is a short story

Short story

A short story is a work of fiction that is usually written in prose, often in narrative format. This format tends to be more pointed than longer works of fiction, such as novellas and novels. Short story definitions based on length differ somewhat, even among professional writers, in part because...

 written by Saki

Saki

Hector Hugh Munro , better known by the pen name Saki, and also frequently as H. H. Munro, was a British writer whose witty, mischievous and sometimes macabre stories satirised Edwardian society and culture. He is considered a master of the short story and often compared to O. Henry and Dorothy...

 (Hector Hugh Munro) between 1900 and 1914 and initially published in his book The Chronicles of Clovis. It has been adapted for opera, film, radio and television.

The story concerns a 10-year-old boy called Conradin, who lives with his strict cousin and guardian

Legal guardian

A legal guardian is a person who has the legal authority to care for the personal and property interests of another person, called a ward. Usually, a person has the status of guardian because the ward is incapable of caring for his or her own interests due to infancy, incapacity, or disability...

, Mrs. De Ropp. Conradin rebels against her and invents a new religion for himself, which centres around idolising a polecat-ferret he calls Sredni Vashtar; a vengeful, merciless god

God

God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....

.