Even with Iron Man 3 behind him, Shane Black isn't looking much further than the world of pulp heroes for his next feature.

Black is the writer and director of the upcoming Doc Savage, an adaptation that was announced years ago but now seems to be gearing up in earnest. To that end, Black is already thinking about casting the "perfect physical specimen" that is the titular Savage — a tall order, literally and figuratively.

"They kind of gotta be tall. He's the perfect physical specimen and when people look at him, they're overawed by the sort of symmetry and perfection he exudes," the filmmaker says in a video interview with IGN (below). "You need someone magnetic and someone a little bit off because that's the fun of the character. He's been secluded from people and kept from any social niceties for so long that he's become a savant."

Another trick to cracking the Savage code: giving the hero some flaws.

"There's an element of goody-goody that we like,"Black says. "But that kind of perfect hero who never makes mistakes is great to a point, and the type of adventure and pulp it represents is so imitated."