The Book Conman is a male dognose.
The Book Conman was an unscrupulous denizen of Duckburg. This fat dognose printed thick-looking books entitled How to Make Money, which he sold for a steep price, when in truth, they contained but one sentence: "Get a job in the mint". After he tricked Scrooge McDuck, the stingy scotsman got back at him by offering him (for no less than fifty dollars) a book supposedly written by him and entitled The Secret of My Millions. On the faith of McDuck's fortune, the Conman bought the book, only to find that it was blank (which, Scrooge said, was only natural, since the title said outright that it was a "secret").
Behind the scenes
The Book Conman only ever appeared in the 1960 story The Secret Book.