This year, Michael Keaton got quite a few positive reviews for his performance in Birdman, but comic fans know him far better as a different superhero: Batman. Starring in both Batman and Batman Returns, Keaton was originally supposed to appear in a third film -- had the studio not decided to replace Tim Burton with Joel Schumacher for Batman Forever.
However, if you'd like a glimpse at what could have been, io9 has uncovered photos of what Keaton's Batsuit for Batman 3 would have looked like had the film been made. Designed by José Fernandez, the suit Keaton would have worn is still in the prototype phase in these photos, evidenced by the grey coloring. However, the iconic bat logo is still present on each costume, with some looking more like armor than others. (However, all of them have a fair amount of emphasis on the ab muscles.)
Keaton's role in Birdman allowed Fox Searchlight to make their own reference to his Batman career in November -- the studio actually released a viral parody trailer for Birdman Returns that was incredibly similar to that of Batman Returns.