Andy Serkis has joined the "Avengers: Age of Ultron" cast, but wouldn't give up details regarding his new role.

Serkis, who also has a mystery role in the upcoming "Star Wars Episode 7" production, confirmed the casting news during an interview with Variety. 

The actor claimed he's working with Mark Ruffalo during the film and explained why the actor needed coaching for the Marvel film.

"Performance capture was used on the previous 'Hulk,' but not to the same extent Mark is using it now," Serkis told Variety.  "There are tools and ways of working with an actor that makes them feel that they own the character. And a character the size of the Hulk needs ownership, which Mark has now."

Unfortunately for fans, Serkis couldn't discuss if his role in "Avengers: Age of Ultron" will be a physical or computer-generated one.

"I'm not at liberty to mention," he said.  "But it's all the same to me. I've never drawn a distinction when playing a role, whether it be live action or performance capture. Acting is acting. It's just basically what you wear to the set that's different."

Little is known about Serkis' upcoming role, but there were reports earlier in June on a potential plot line for Ruffalo.  According to the Latino Review, The Hulk and Black Widow will have a budding romance throughout the film.

"Well, in the party scene at Avengers Tower, we discover that Banner and Black Widow kinda have a thing for each other," Latino Review reports.  "Banner is afraid to consummate anything with her for fear of hulking out and hurting her. He doesn't trust himself...Banner and Black Widow are definitely into each other."

"Avengers: Age of Ultron" is currently in production and is slated to hit theaters on May 1, 2015.