C-3PO, like all protocol droids, specializes in interpretation and communication between the various intelligent species and droids of the galaxy. He is fluent in over six million forms of communication and especially enjoys the nuances of human interactions. While he gives the appearance of being a fussy and cowardly droid, 3PO is loyal to his masters and counterpart, R2-D2.
When Anakin Skywalker was a young boy, he built C-3PO from parts he'd scavenged in Watto's junk yard. Since then he's worked for some of the most pivotal people in the galaxy including Padmé Amidala , Bail Organa, Luke Skywalker, Princess Leia,
A Wookie from the planet Kashyyyk, Chewbacca was a hero of the rebellion from the earliest days. Assgned to Yoda as a bodyguard during the clone wars, Chewie helped him escape when the Emperor called for the death of all Jedi. Later Chewbacca met Han Solo and the two became friends and copilots of the Millennium Falcon.
In the final weeks before the final version of the Star Wars Origami manuscript was due, we realized two main characters were missing. Chewbacca and C-3PO. With deadlines approaching I scrambled to come up with a 3PO face, and the famous “Walking Carpet”. One drawback of origami is that it is impossible to create a model with the level of detail required to differentiate between say Harrison Ford and Mark Hammal. The other problem is Origami has been around for centuries so I had to reinvent the human form without copying another artists' work. Not an easy task. I came up with a new generic humanoid form for Chewie but Lucasfilm didn't think the C3PO face was up to par. For the record, neither did I. As a compromise between deadline and leaving him out we decided to use the humanoid for both with some minor differences. One of these days I'll have to go back and rework the 3PO face. Maybe someday you'll see it here.