The Jawa are relatively benign characters from Luke’s home planet of Tatooine. They tend to travel in packs (making for a good group costume) and don’t treat droids too well. They are a very recognizable race from Star Wars- even if you didn’t know their name. They are small- so they are a great costume for the kids.
This is a pretty simple costume to pull off. You just need the brown hooded robe, a black mask, and I have seen yellow or red eyes. Here is a great example.