Doctor Fate is a succession of DC Comics sorcerers who also generally function as superheroes. The original version was created by writer Gardner Fox and artist Howard Sherman, and first appeared in More Fun Comics #55 (May 1940).
This was Kent Nelson, the best known and longest used Doctor Fate. He was the son of an archaeologist who died discovering the tomb of the mystical being Nabu [Hence the title of this post -- Ed.]. The orphaned boy was trained by the ancient entity in the arts of magic.
Of course, as a kid, I didn't know any of that. I just knew that Doctor Fate had a wicked-sweet costume and did karate-chops on purple demon-squids or something.
Below is my rendition of the hero, sticking relatively close to the original. They redesign the costumes every other week anyway, so I'm sure it's close enough.
Click on the thumbnail for a larger view.