The giant rat of Sumatra is a fictional giant rat, first mentioned by Arthur Conan Doyle in "The Adventure of the Sussex Vampire".
[1] 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The name of the rat and its implied unpublished history were later used in Sherlock Holmes pastiches by many other writers.
[1][2][3] 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,[4] Doyle has Sherlock Holmes declare, as an aside, to Dr. Watson: Matilda Briggs was not the name of a young woman, Watson, ...
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: