William Hurt and Robert Downey Jr. entirely improvised the post-credits scene of The Incredible Hulk. Back in 2008, Marvel Studios burst onto the scene with Iron Man. The movie was a critical and box office hit and set the foundation for what the Marvel Cinematic Universe would become, establishing what many would quickly come to expect from the latest MCU offerings.
It didn't take long for this to be put to the test either, as The Incredible Hulk arrived in theaters just a few months later. After seeing Robert Downey Jr.'s charismatic portrayal of Tony Stark, audiences were treated to Edward Norton's take on Bruce Banner aka Hulk. While mostly standalone, The Incredible Hulk became tied to the MCU through its post-credits scene. Downey reprised his role as Tony Stark in a scene with William Hurt's Thunderbolt Ross that teased the Avengers Initiative. The scene was a big deal, but many may not know that it was completely improvised.
This fact was confirmed by Hurt himself several years ago in an interview with Collider. He revealed that when he and Downey arrived to set that day that not a single line of theirs was written down. Instead, both of the veteran actors were free to say what they believe the character would say at that moment. There may have been some parameters over why the conversation was taking place, but Hurt and Downey were otherwise responsible for the quips that their characters traded. For more improvised scenes in Marvel movies, check out the latest Screen Rant video at the top of this post.
The good news for Marvel is that Hurt and Downey were able to deliver a great scene all on their own in their first bit of screentime together. This was the lone time that Hurt appeared in the MCU too until Captain America: Civil War in 2016. He made his return in the movie and once again worked with Downey as Stark sided in favor of the Sokovia Accords. Hurt's most recent MCU appearance was at Tony Stark's funeral in Avengers: Endgame, bringing this relationship full-circle. However, Norton's differences with Marvel cut short his time in the MCU and chances for such interactions.
The free-reign that Hurt and Downey received may be surprising to some, but the MCU was very different when The Incredible Hulk was released. These scenes have since evolved to become even more prominent than they were early on. Even though the shawarma scene for The Avengers was a last-second addition, most of Marvel's post-credits scenes are planned out. Some of these have just been comedic beats to the movies on, but others directly set up future films. Marvel has even used actual footage from an upcoming movie as a post-credits scene on more than one occasion too. But, improvising a scene completely is not a common practice for them.