Question: who played the big guy in guardians of the galaxy

title: Guardians of the Galaxy (film)
text: Vin Diesel as Groot : A tree - like humanoid who is the accomplice of Rocket . Diesel stated that he provided the voice and motion capture for Groot , after originally being in talks to star in a new Phase Three Marvel film . Diesel also provided Groot 's voice for several foreign - language releases of the film . Krystian Godlewski portrayed the character on set , though his acting was not used in the final character CGI . On the character , which Gunn based on his dog , Gunn said , `` All the Guardians start out the movie as bastards -- except Groot . He 's an innocent . He 's a hundred percent deadly and a hundred percent sweet . He 's caught up in Rocket 's life , really . '' Gunn added that the design and movement of Groot took `` the better part of a year '' to create . Gunn added , `` The ways in which Vin Diesel says , ' I am Groot , ' I am astounded . All of the ' I am Groots ' that were earlier voices did n't sound very good at all ... Vin came in and in one day , laid down all these ' I am Groot ' tracks , and he 's a perfectionist . He made me explain to him with ever ( sic ) ' I am Groot , ' exactly what he was saying ... It was amazing when we first put that voice in there how much the character changed and how much he influenced the character . '' Regarding the limited words used by Groot , Diesel said in many ways this was , `` ... the most challenging thing to ask an actor to do . '' Diesel found an emotional note in his performance , invoking the death of his friend and Fast and Furious co-star Paul Walker , saying , `` This was in December ( 2013 ) , and the first time I came back to dealing with human beings after dealing with death , so playing a character who celebrates life in the way Groot does was very nice . '' Groot 's form and size - changing abilities are seen , with Gunn stating that he has the ability to grow in the film .