Re: Give Robin Williams a role
I don't picture him as Riddler, but he could easily play a smaller, much more low-key character. Maybe something like Rupert Thorne or even Penguin, functioning in the story similar to how Falcone and Maroni did in the previous two films.
O Captain! My Captain! Rise up and hear the bells.
Rise up, for you the flag is flung, for you the bugle trills.
For you bouquets and ribbon'd wreaths, for you the shores a-crowding.
For you they call, the swaying mass, their eager faces turning.