The Guardians of the Galaxy news from Marvel confirms that Bradley Cooper will be voicing the character of "Rocket Raccoon."  This was officially announced in the Marvel website last August 30:

Academy Award-nominated actor Bradley Cooper has officially joined the cast of Marvel's "Guardians of the Galaxy," lending his voice to the fan-favorite raccoon that will join Peter Quill (Chris Pratt), Gamora (Zoe Saldana) and Drax (Dave Bautista) on their epic adventure.

Photo: It's official, Marvel fans! Bradley Cooper has joined the cast of Marvel's Guardians of the Galaxy as... https://t.co/UoxKkpcMsG

— Marvel Entertainment (@Marvel) August 30, 2013

The 38-year old actor is best-remembered for his role as Phil Wenneck in "The Hangover" movies and Templeton "Faceman" Peck in "A-Team", as well as his role as Will Tippin in the hit TV series "Alias."

Guardians of the Galaxy's "Rocket Raccoon" is a genetically-engineered critter who excels in tactics and is an expert marksman.   The movie is said to be the tenth installment in the Marvel Cinematic Universe, following other superhero hits like Thor, Captain America, Iron Man, The Incredible Hulk, and Avengers, although producer Kevin Feige sees it more as a standalone film.

IMDB provides a summary of the plot: "A jet pilot gets stranded in space, and must unite a diverse team of aliens to form a squad capable of defeating cosmic threats."

In an interview with CinemaBlend last Feburary, executive producer Victoria Alonzo was asked about how they intend to portray Rocket Raccoon and another character Groot (a tree) in the movie, whether it would be CGI or motion capture.  She said, "We're going to do a combination. You can't do any motion capture with a raccoon - they won't let you put the suit on [laughs]."

She added, "But we will do rotomation, probably, for some of the behavior.  Rocket will have his own personality, of course, and clearly we can't do mocap on a tree, per say, but we definitely will have performers to emulate what James Gunn will lead to be the behavior and the performance."

In the movie with Cooper are: Vin Diesel (the voice of Groot); Zoe Saldana (Gamora); Dave Bautista (Drax the Destroyer); Lee Pace (Ronan the Accuser); Michael Rooker (Yondu); Karen Gillian (Nebula); Djimon Hounsou (Korath); Benicio del Toro (The Collector); John C. Reilly (Rhoman Dey); and Glenn Close (Nova Prime).

More Guardians of the Galaxy news will come up as it continues filming.  The movie will come to theatres on August 1, 2014.