Giant rat of Sumatra

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 The name of the rat and its implied unpublished history were later used in works by many other writers.

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:

How the ship, the mammal, and the Indonesian island are associated is not specified. Rats commonly colonize ships, and so there is an obvious line of speculation.

Another train of thought follows the reasoning that Matilda Briggs actually was the name of a young woman as well as a fictional ship—for the famous "mystery ship," the Mary Celeste, which was found abandoned at sea in 1872, had sailed under the command of Captain Benjamin Briggs, whose daughter, Sophia Matilda Briggs, was a passenger on the doomed merchant brigantine. Doyle was certainly familiar with the Briggs family, for in the January 1884 issue of the Cornhill Magazine, when he was but a 25-year-old ship's surgeon, he had published a short story about the mysteriously abandoned Mary Celeste titled "J. Habakuk Jephson's Statement". As it was a work of fiction, Doyle did not adhere strictly to the facts; he renamed the ship Marie Celeste, the captain's name was given as "J.W. Tibbs", and the fatal voyage was said to have taken place in 1873—but his story proved so popular and influential that many people to this day still refer to the vessel as the Marie, rather than the Mary, Celeste.

A number of species of large rats have existed and, in some cases, still live on Sumatra, Papua, East Timor, and other Indonesian islands:

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