Cluemaster

Arthur Brown is obsessed with clues, and he intentionally leaves behind clues at all his crime scenes. Though his clues are technically not riddles, he is basically a poor man's Riddler.

His main contributions to Batman comics are forming the Injustice League with a group of lesser-known villains, and fathering Stephanie Brown, aka Spoiler, who briefly served as Robin.

Pros:You can take most potential Riddler stories and turn them into Cluemaster stories.

Cons: But they wouldn't be as good.

How I'd do it: I probably wouldn't. Any Cluemaster story would feel like a cheap version of a Riddler story. And having him as a cameo would require too much time to explain his impulse to leave clues behind.

Casting Guesses: I tend to think of him as an older guy, father of a teenage daughter. Character actor Gregg Henry could fit the part.

Verdict: Not going to happen. If they ever started making Robin movies featuring Tim Drake, he'd probably have to show up. But in Robin-less Batman, he's a nobody.