In 1968, Hannah-Barbera took Mark Twain's characters and thrust them into various make-believe fantasy worlds. In this live-action/animated series, the actors were superimposed over animated backgrounds. It's an obscure cartoon I barely remember. The New Adventures of Huckleberry Finn
This is the very reason J.D. Salinger sued to block the publication of a so-called "new" take on his Catcher in the Rye.
