The giant rat of Sumatra is a fictional giant rat, first mentioned by Arthur Conan Doyle in "The Adventure of the Sussex Vampire". As part of the tale, the protagonist, Sherlock Holmes, declares that there is a "story" connected with this rat, presumably a detective case he has handled. The name of the rat and its implied unpublished history were later used in Sherlock Holmes pastiches by many other writers.

Original reference

In "The Adventure of the Sussex Vampire", first published in the January 1924 issues of The Strand Magazine in London and Hearst's International Magazine in New York, Doyle has Sherlock Holmes declare, as an aside, to Dr. Watson: "Matilda Briggs was not the name of a young woman, Watson, ... It was a ship which is associated with the giant rat of Sumatra, a story for which the world is not yet prepared." How the ship, the mammal, and the island of Sumatra are associated is not specified.

In Sherlockiana

A number of authors of Sherlockiana have endeavoured to supply the missing adventure of the giant rat of Sumatra, either in non-canonical Holmesian fiction, or as references to the tale in other fictional settings: