Gentleman Ghost is not a character I know a lot about, but I have to confess he's one of the most fascinating looking characters in comics. That pallid color scheme, the dapper evening wear, the spry top hat, the cool cane, the ever-present monocle, and the always absent head add up to one of comics most chilling images. He's a creepy looking creation for sure. The late great Joe Kubert seemed to have the magic to draw him with real panache.
The Gentleman Ghost debuted in Flash Comics #88. Above is a sample page. Here's an exceedingly groovy link to his second story from Flash Comics #90.