This is a bit different from all the other examples on this list, but in “Avengers: Age of Ultron,” Andy Serkis was never going to be cast as Klaw. The character is also seen in (and meets his end in) “Black Panther,” but Serkis was originally just there to help Mark Ruffalo and James Spader get used to acting in motion capture.
Serkis is famous for acting as Gollum during the “Lord of the Rings” movies, so who better to teach others? Well, producers happened to find fan-art of Serkis as Klaw, and since they still needed an actor for the role, they figured it would work.
Talking About Armor
Batman's defining feature is his suit of armor, and for the 1989 “Batman” film, the producers and set designers gave Bruce Wayne a couple of other suits of classic medieval armor. At one point, romantic lead Vicki Vale and her fellow reporter Alexander Knox are wandering around the beautiful Wayne manor and catch sight of the armor.
Robert Wuhl, who played Knox, ad-libbed his lines. This includes things like “this guy must have been the king of the wicker people.” And stating that “the more they have, the less they're worth,” in regards to Wayne's bank accounts. Of course, Wayne was listening the whole time, taking the comments in stride. He even gives Knox a grant for his work.
Mark Ruffalo Gets a Few Chances to Show Off
While a lot of press goes to Iron Man, Captain America, and some of the newer characters, there's no ignoring the big green elephant in the room. Bruce Banner is smart, strong, and has surprising depth to his character. His actor, Mark Ruffalo, got to add a few of his own elements, such as the earth-shaking roar that brings Iron man back to consciousness.
He also added a small moment when he focuses on a cradle, during his meeting with Black Widow. This gets expanded on in the sequel when he and Natasha Romanoff bond over their inability to have children. We don't know if Ruffalo knew about this detail, or if the producers ran with his unscripted moment.
That Guy's Playing Galaga
One of the most memorable scenes in the first “Avengers” movie is when Tony Stark walks into the Helicarrier's bridge and points out a guy playing the classic alien-fighting video game Galaga. At the end of the scene, the same SHIELD employee turns back to his video game.
The original line was an ad-libbed joke by Downey, but director Joss Whedon found the employee a little sketchy in the scene, so he added a scene of the employee returning to his game once the main characters departed. Not only did the scene add a brief moment of notable humor, but the entire shot of the game returning was never even in the script.
Even Animated Superhero Films Have a Place
It's a lot harder to throw something into an animated film since each and every moment is deliberately drawn, sculpted, or animated. “Big Hero 6” manages to do it in a few different ways, however. T.J. Miller ended up ad-libbing most of Fred's dialogue to give it a more personal touch. In addition, you might notice Cass has some goofy facial expressions, especially while talking about her extra-spicy hot wings.
This comes from the voice actress herself, Maya Rudolph, who made faces while recording her lines. They were copied directly onto the character thanks to the animators getting their hands on footage of her during recordings.