Mark Ruffalo has been working with Andy Serkis to improve the Hulk in Avengers: Age of Ultron.
Ruffalo is set to reprise the role of Bruce Banner in the second Avengers film, a part that sees him do a lot of motion capture work.
And the Oscar nominated actor has revealed that he has teamed up with Serkis - who has done motion capture work on The Lord of the Rings, The Hobbit and Rise of the Planet of the Apes.
Posting on his Twitter account, Ruffalo said: "Well, I have been working with the great @AndySerkis on the big green boy and he is going to be even better".
Avengers: Age of Ultron will be the second time Ruffalo has taken on the role of Banner - we were introduced to his character for the first time in Avengers Assemble.
Filming is currently underway on Age of Ultron, as he reunites with Robert Downey Jr, Scarlett Johansson, Chris Evans, Chris Hemsworth and Jeremy Renner.
The movie will see Joss Whedon return to the director's chair, as well as pen the screenplay.
Filming on Age of Ultron will take the cast and crew to Italy, South Korea, South Africa and London.
Avengers: Age of Ultron is released 24th April.
Tagged in Mark Ruffalo Avengers