In the TV Spot No. 17, from Marvel’s Guardians of the Galaxy you see a bit more of Groot and his relationship to Rocket.  Though what interested me most about the trailer is the way Rocket speaks.  He says: “Yes, you did, I just saw you do-ing it.  Why you ly-ing.”

And he sounds awfully ethnic, in fact, Hispanic.  Since Rocket is voiced by Bradley Cooper it’s seems unlikely that’s the feel he was going for; but don’t take my word for it, listen around the 0:04 mark.

It’s an odd bit of voice work.