Star Wars Episode 2: Attack of the Clones - Sebulba- Twice!
When Obi-Wan enters the bar and meets the big Dexter guy with 4 arms wait untill they sit down and start talking- once they do pay attention to the background behind Dexter. Sebulba will run into the booth- cool, then watch again because Sebubla will do it again! He will do it the same exact way! Behind Obi-Wan there is a Greedo! Cool huh?
I don't know if you are a huge Star Wars fan like I am, but it sure does rub me the wrong way that you said "a Greedo." It was not proper Star Wars Talk. The right term was "a Rodian." Obviously, George can't keep putting future characters in the early movies, so he made many many species. This way, it makes his made up galaxy look bigger and more colorful.
That is not a Rodian behind Obi-Wan, it is a Nuknog, and, as long as we're counting Dugs, there are two more behind Obi-Wan. That said, this should not be posted as a slip-up as these characters were intentionaly placed in the movie. It isn't even an easter egg because this would be mundane in the Star Wars universe and even more commonplace on Coruscant.
Actually, according to the director's commentary, he says that the character behind Obi-Wan is Sebulba. Yes, it is a dug. I didn't see a "greedo", though. I'll have to watch that scene again. But it is Sebulba because the director says so. Listen to the director's commentary for that scene and you'll find out.