Ulysses Klaw was only a couple of days ago confirmed for Avengers: Age of Ultron. Rumors about his appearance in The Avengers 2 have started to pile up since Andy Serkis was announced to be on board with Joss Whedon's sequel.
The news came sort of silently and impromptu, since neither Marvel nor Disney made a public announcement. But it's solid info we can surely rely on.
Stitch Kingdom was graced by the studios with a collection of behind-the-scene images. And guess what: Andy Serkis's character is featured in one of them.
The description clearly points out the still showcases Ulysses Klaw. Check it out here.
Who is Ulysses Klaw?

According to the comic book, Ulysses Klaw is a Dutch scientist at war with Black Panther, and a classic enemy of both the Avengers and the Fantastic Four team. His superpower resides in the fact his very being consists of solidified sound. He also carries an artifact "“ a gun-like prosthesis "“ that turns sounds into images.

