Was trying to think of ways to add more familiar aliens to the Sequel Trilogy without having to shoot any new footage. Here are some ideas:
For Maz’s Castle, I really only have one strong idea so far.
So, there is a shot from the cantina scene in ANH where Greedo faces the camera when the bartender tells Luke he can’t bring in any droids. In that shot, Greedo is on the left side of the screen, and he slowly turns back to the table he is at for the duration of the shot.
In TFA, when Maz shouts “Han Solo!”, there are three quick reaction shots of bar patrons turning to face him. In the third shot, at 0:57:45, three patrons quickly turn to camera. You could potentially rotoscope Greedo out of the original scene and put him into this one, covering up one of the two patrons sitting on the sides. Then, you could reverse the shot and speed it up slightly to have him turn to face camera like the rest. Also, you would need to recolor his costume and skin so he would be clearly seen as a different Rodian. You also might need to rescale the shot some in order to match shot to the scale of Greedo.
I think Canto Bight would be another good place to add some familiar aliens, but the ‘how’ is a little more difficult. I think one of the simplest ideas might be to take a shot of Jabba from ROTJ and add a Hutt somewhere amongst the casino-goers, which seems like an appropriate species to appear.
This clip of Canto Bight with additional deleted shots has a few shots that might work for this idea. Around the 1:36 mark, there are three brief CU shots of casino patrons that I think Jabba could be added to. I think one shot of Jabba that is usable would be when he stuffs a frog in his mouth. There might be a better option somewhere else though. You could rotoscope him out of that shot and recolor/add dinstinct features to him to help make him look like a different Hutt. You would also need to mask out parts of the foreground patrons that Jabba can’t cover up, and also maybe flip the shot in order to have Jabba facing the opposite side that he does in ROTJ.
It would be great if we could get some actual alien masks/gloves and film some quick shots in front of a green screen, but until then I think these are some potentially doable ideas that could add just a pinch of familiarity. Luckily, both of these shots are very brief, from less to a second to four or five seconds at most.