Success Leaves Clues

This villain could be seen as a deep cut. Unless you're a Batman fanboy junkie. Created in 1966, by Gardner Fox and Carmine Infantino, the Cluemaster, Arthur Brown, is really nothing more than a Riddler rip-off. In his debut in Detective Comics #351, Arthur Brown is a former game show host who decides to commit crimes and leave clues to help the police for some reason. This is not technically the same modis operandi as the Riddler, as the clues are not in the form of riddles, but this is basically semantics. The Cluemaster's goal is to uncover the identity of Batman and Robin, somehow. 

Obviously, he is caught and thrown in Blackgate Prison. There are a few other appearances where he joins various super villain teams, to no success. But in Detective Comics #647 Brown is released from Blackgate. This time around he performs heists without leaving clues behind. However, someone else does, which ruins the new crimes and narrowly puts him back in prison. 

This run in Detective Comics not only makes the character more relevant, but also introduces a character that actually makes the Cluemaster important. Stephanie Brown, Arthur Brown's daughter, is revealed in Detective Comics #648, after being teased in the previous issue. 

Stephanie Brown begins her career as the Spoiler, a costumed persona created with the specific goal of ruining her father's criminal career. She leaves behind clues when the Cluemaster stops doing so himself. Eventually, the Spoiler teams up with Tim Drake's Robin, is reluctantly trained as a new Robin by the Batman, gets fired, and then becomes the new Batgirl, only to eventually become Spoiler once again. Its a pretty long journey for her that does come full circle.

As for the Cluemaster, his only claim to relevancy in the Batman universe is through his daughter. He has a tour as a member of the Suicide Squad, and attempts a few more times to put together a gang, this time brought down by his own daughter, the new Batgirl. Eventually, the similar M.O. gets him killed by the Riddler, who sees him as a copycat.