Ser Jorah Mormont
Book Jorah Mormont and Ian Glen, who plays him on the show, don’t look much alike, as evidenced by the photo. Unsurprisingly, he is described in the book as “not a handsome man.” Of course, his infection with Greyscale is his most notable narrative in the show (apart from his love and dedication to Daenerys). So you might be astonished to learn that it never happens in the books. He is, of course, still alive in the novels.
Syrio Forel
Surprisingly, given that he appears in only three episodes of the show, hardly much of Syrio Forel’s story is altered from the books. His appearance, of course, had changed dramatically. Mittos Yerolemou, who plays him, is as inconsequential as the description. However, his beaked nose and bald head are absent from the show. His fate is unknown in both, however Arya (who keeps his memory alive in both) believes he is dead.