don't forget the deformed human guy who picks a fight with Luke "he doesn't Like You, I don't like you either!" and those twin girls with the cleopatra braids, in fact there are quite a few humans in that scene, apart from the Jawas and Sand-people, the cantina sequence is the first real chance we get to see different alien species in the trilogy, which is probably why the aliens stand out so much from the humans.

I'm pretty sure I read that most of the creatures in that scene were shot and added in post production to beef up the scene.