Darth Fanon

Darth Fanon was a Sith Lord whose identity wasn't revealed until everyone in the Galaxy made a guess at it. Turns out he was just some Jedi nobody remembered from a hundred and fifty years before.

Behind the scenes
Before Darth Fanon's true name was revealed, it was speculated by rabid fanboys (and hopeful fangirls) that he was just about dude in the Star Wars galaxy. When it turned out that his true identity was in no way juicy or scandalous, his nickname quickly changed to Darth Disappointment.