C-3PO

C-3PO was a Cybot Galactica 3PO-series protocol droid built by Anakin Skywalker on Tatooine.

The Clone Wars
"Oh my! Mistress Padmé! Not this again. I've hardly had time to dry off your gown after the last time these men paid you a visit. Oh dear, oh dear."

- C-3PO, catching Padmé Amidala in the aftermath of a blowbang

Rebellion era
C-3PO worried over R2-D2 during the Battle of Yavin, and communicated with the droid until Artoo was rendered inoperable by a laser blast. Afterwards, Threepio offered his parts to help repair Artoo, and when the droid was fully functional again he teased the golden droid for weeks.

C-3PO attended the Wedding of Han Solo and Leia Organa after the Battle of Endor alongside R2-D2, Wedge Antilles, Lando Calrissian, Luke Skywalker, and Chewbacca. Even the droids exhibited happiness at the occasion.

New Republic era
C-3PO helped raise Ben Solo, the son of Han Solo and Leia Organa, and Ben sometimes considered the droid more of a present parent than his actual parents. He served as an excellent storyteller to the youth in lieu of his parents, regaling Ben with tales of the Mud Moon of Panna, the Lost Prince of Tammuz-an, and the Dread Pirate Kybo Ren of Tarnoonga.

He accompanied Luke Skywalker and Lor San Tekka to Devaron, and conversed with Kivas alongside Tekka while Skywalker returned to the Temple of Eedit with Kivas's daughter, Farnay.

Resistance era
"See-Threepio told me about you. He said you haven't spoken since&mdash;in a long time. I wonder what's going on in there?"

- Jessika Pava, to R2-D2

As of this era, Threepio had developed idiosyncrasies since his last memory wipe. Serving in the Resistance base on D'Qar, he was often found with BB-8, particularly when Poe Dameron was absent reaping the benefits of his good looks and charm. He regaled Jessika Pava with tales of Luke Skywalker and R2-D2, prompting Pava to later seek out the latter and attempt to awaken him from his low-power dormancy, and later met Rey as one of numerous heroic figures the former scavenger encountered.

Description
C-3PO was a golden droid, possessing the limbs that astromech droids such as R2-D2 lacked. He had an electronically-filtered voice that carried a prissy, worrisome tone. Threepio had a pruriency filter that erased certain insults.

Jessika Pava characterized Threepio as fussy, and R2-D2 saw him as prissy and worrisome. Possessing idiosyncrasies developed since his last memory wipe, he had a somewhat poetic manner, and spoke about concepts such as the experience of dreams among droids, whereas his counterpart R2-D2 was more pragmatic. Despite this, Artoo treasured their friendship and considered Threepio to be very dear to him, believing the droid would short-circuit if anything happened to Artoo. Threepio served as an excellent storyteller.