I knew Marty Feldman only as a funny supporting cast member in comedies. His bulging wide eyes that looked in different directions made him instantly recognizable as can be seen in this clip from Young Frankenstein (1974) with the late Gene Wilder where he plays Igor, his debut film role that made him known to a worldwide audience.
Here is a clip from the film where we see him for the first time.
A 2008 BBC documentary about him reveals a much more versatile person who was an extremely successful, much sought after comedy writer on British radio before he became a performer with even a TV series named after him and who had members of the Monty Python troupe writing for him, and this led him to Hollywood where he was a leading man and director in films that, unfortunately, were not successful. I also learned that he was not born with his trademark eyes but they became that way following surgery for an overactive thyroid.
Here’s the documentary.