xhonzi said:

There seem to be 3 or 4 classifications:

Human or might as well be human Character:
Luke
Ackbar
Greedo
Twi'leks
Yoda

Alien, but still pretty human (maybe humans with learning disorders, or too much TV during development years)
Chewie
Ewoks
Sandpeople
Gamorreans

...

I would put Chewie in the "might as well be human" category. He's like a frighteningly huge hairy biker with a bad attitude, who also happens to be good at fixing engines.

Ewoks are akin to a lost tribe of primitive humans hidden in a remote part of a South American rainforest - the Empire's presence on their planet being their first contact with the "modern" world.