The Cheshire cat was a character in the book Alice's Adventures in Wonderland, by human author Lewis Carroll. The Cheshire cat was distinguished by its smile, which would remain even after the rest of the cat had disappeared.

Seven-year-old Robin Lefler adopted the nickname "Cheshire" (or "Ches") after reading Carroll's books with her mother, Morgan (who took the nickname "Alice"). (NF short stories: "Lefler's Logs", "Alice, on the Edge of Night")

This fictional character had also been created in the mirror universe, as in 2277, Marlena Moreau refers to a "Cheshire cat grin." (TOS novel: The Sorrows of Empire)

In 2370, Miles O'Brien said that he thought Julian Bashir's smile was "just like the Cheshire cat" of Carroll's novel. (DS9 novel: Warchild)