C-3PO (TROS)

C-3PO, sometimes spelled See-Threepio and often referred to simply as Threepio, was a 3PO-series protocol droid designed to interact with organics, programmed primarily for etiquette and protocol. He was fluent in over six million forms of communication, and developed a fussy and worry-prone personality throughout his many decades of operation. Along with his counterpart, the astromech droid R2-D2, C-3PO constantly found himself directly involved in pivotal moments of galactic history, and aided in saving the galaxy on many occasions.