 The switch from Mandarin to Obadiah Stane was done after Bridges was cast in that role, with Stane originally intended to become a villain in the sequel.The Crimson Dynamo was also a villain in early drafts of the script.Favreau felt it was important to include intentional inside references for fans of the comics, such as giving the two fighter jets that attack Iron Man the call signs of "Whiplash 1" and "Whiplash 2", a reference to the comic book villain Whiplash, and including Captain America's shield in Stark's workshop.