Naturally, many details are still unknown regarding Spider-Man's forthcoming debut in the Marvel Cinematic Universe. Some site speculate that reshoots are happening for Spider-Man to appear in the end-credits stinger for Avengers: Age of Ultron. Specifically, rumors state that at the end of the film, Captain America and Iron Man venture down separate paths to each form their own Avengers teams. When each puts out the call for new heroes to join their respective teams, one of the superheroes that answers the call will reportedly be good ol' Spider-Man. A more persistent rumor is that Spider-Man first shows up in the Marvel Cinematic Universe in Captain America: Civil War. If that film is indeed the first appearance for Spidey, which costume should he wear? The classic blue and red suit or the Iron Spider costume that Tony Stark builds for him? It's really a question of how close will Marvel and the Russo Bros. adhere to the source material from Mark Millar and Steve McNiven's 2006 Marvel miniseries.