Avengers: Endgame star Mark Ruffalo -- who plays Bruce Banner/Hulk in the Marvel Cinematic Universe -- is not surprised the franchise of comic book-based films has been a success.

The success Ruffalo and his co-stars have enjoyed as part of the MCU has reportedly served as the inspiration for Robert Bilott, his character in the upcoming film Dark Waters. In a recent interview with The Hollywood Reporter, Ruffalo offered his thoughts on what gives Marvel its appeal, likening Bilott to everyone's favorite big green behemoth.

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"It's no mistake that people have fallen in love with the Marvel universe," said Ruffalo. "Because they want to see a world that's just. They want to see people who are fighting for the little guy, and on behalf of the little guy. And [Bilott] is a little guy fighting on behalf of other little guys."

Ruffalo began playing the role of Bruce Banner in 2012's The Avengers -- taking over for Edward Norton, who previously played the character in 2008 the 2008 MCU film The Incredible Hulk. Ruffalo has since reprised his role in Iron Man 3, Avengers: Age of Ultron, Thor: Ragnarok, Avengers: Infinity War, Captain Marvel and, most recently, Endgame. While his future as the Hulk is currently unclear, there is speculation he could appear in Disney+'s upcoming She-Hulk series in some capacity.

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Directed by Todd Haynes, Dark Waters stars Mark Ruffalo, Anne Hathaway, Tim Robbins, Bill Camp, Victor Garber, Mare Winningham, Bill Pullman, William Jackson Harper and Louisa Krause.

Directed by Joe and Anthony Russo, Avengers: Endgame stars Robert Downey Jr. as Iron Man, Chris Evans as Captain America, Mark Ruffalo as Bruce Banner, Chris Hemsworth as Thor, Scarlett Johansson as Black Widow, Jeremy Renner as Hawkeye, Brie Larson as Captain Marvel, Paul Rudd as Ant-Man, Don Cheadle as War Machine, Karen Gillan as Nebula, Danai Gurira as Okoye and Bradley Cooper as Rocket, with Gwyneth Paltrow Pepper Potts, Jon Favreau as Happy Hogan, Benedict Wong as Wong, Tessa Thompson as Valkyrie and Josh Brolin as Thanos. The film is available on Digital HD, Blu-ray and 4K UHD