So … why James Spader?

It's a question a lot of fans unfamiliar with the actor's work asked when he was announced as the titular robot nemesis of Marvel's The Avengers: Age of Ultron. For one, Spader isn't exactly a marquee name these days, despite his work on NBC's The Blacklist. Besides, Ultron's just a robot, right? Why not hire an A-list actor for the voice work, a la Bradley Cooper as Guardians of the Galaxy's Rocket Raccoon?

Foolish considerations, all of them. Marvel Studios President Kevin Feige tells The Huffington Post that Ultron "will be more than a voice role," with Marvel planning to capture Spader's "face and his body to create a whole performance." When imagining Spader's snarling grin and snarky one-liners, it's easy to see why both of those fit well within Marvel's vision of Ultron.

"He's a very unique and incredibly exciting and unpredictable actor," Feige said. "And Ultron in the comics is a robot, but what's cool about him in the comics — and certainly how Joss Whedon is interpreting him for the movie — is that he is much more than just a robot. That he's infused with much character. And I don't want to say too much, but you can imagine James Spader will be very dynamic in his portrayal of the character."

"We did not hire James Spader to do a robot voice," he added.

The Avengers: Age of Ultron hits theaters on May 1, 2015.