Mark TWAIN was an American author and humorist who is best known for his novel 'The Adventures of Tom Sawyer' and its sequel, 'Adventures of Huckleberry Finn'. He is also credited with creating the character of the Jumping Frog, which became a popular figure in American culture. TWAIN's work has been praised for its wit and satire, and he is considered one of the greatest American writers of all time.