Storyboard and concept artist Thomas Nelson updated his website with some storyboards and artwork that he created for Guardians of the Galaxy. One of the characters in this concept art is Lord Tantalus, a character that did not appear in the film. He was originally in the script though.
Gunn was probably saving Lord Tantalus for the sequel since his backstory is fairly complex. Some of the other characters here have similar, but different looks than we saw in the film.