Had some insomnia last night so I doodled this until I got tired. It was mostly drawn with ink & brush; I think I only used pencil for the outline because if I was going to mess up, I'd rip it up anyway.
Riddler's a tricky character. I prefer the Frank Gorshin/John Glover versions but I've hated the green leotards & ballet slippers since I was a kid. Suit looks better on him IMO sans so many question marks.
That's just my opinion really...
In any regard, I hope you like it and thanks for taking the time.