Marvel has finally made Vin Diesel’s voice role as Groot in Guardians of the Galaxy official.
After months of teasing and misdirection (by both Marvel Studios president Kevin Feige and Diesel, on his Facebook page and in interviews), Marvel finally confirmed the Fast and the Furious /Riddick star will be rounding out the Guardians team as the voice-actor for tree-creature Groot (negotiations were leaked in August, see "Vin Diesel in 'Guardians'").
Diesel will join Bradley Cooper, who has been cast as Rocket Raccoon, in the voice-over booth (see "Cooper, Olsen in Talks for Marvel Movie Roles").  Diesel has lent his signature baritone growl for vocal work before, on several video games as well as for the title role in the 1999 animated film The Iron Giant.
Guardians of the Galaxy follows the unlikely intergalactic team of Star-Lord (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista), Rocket Raccoon (Bradley Cooper) and Groot, as they are forced to join together to defeat a cosmic force of epic proportions.  Directed by James Gunn, Guardians of the Galaxy will release on August 1, 2014.
Marvel is offering a new Guardians of the Galaxy comic for Free Comic Book Day in May ("FCBD 2014 Gold Comics Announced").