In the mirror universe, Samuel Langhorne Clemens was a Terran author who lived during the 19th and 20th centuries. Better known by his pen name Mark Twain, his novels included The Adventures of Tom Sawyer.
After the Terran Republic was conquered by the Klingon-Cardassian Alliance in 2295, the Alliance banned many "decadent" forms of Terran art such as the novel Les Misérables by Victor Hugo. However, this does not seem to have been the case with Clemens' work. When the archaeologist for hire Vash was a child, someone had read The Adventures of Tom Sawyer to her. While being fired upon by Alliance personnel on Celtris III in 2371, Vash claimed that she felt like "Becky Thatcher of Old Earth, being chased through unmapped caverns by Injun Joe. If Becky had a disruptor rifle, that is." (TNG - Mirror Universe novel: The Worst of Both Worlds)
- All indications suggest that the mirror versions of both Clemens and The Adventures of Tom Sawyer are identical to our own.