42-RST, also known as Rusti, functioned as a translator droid and was under the "ownership" of Bungo Bung, who served as the captain of the Chubby Gundark, a SoroSuub freighter.
Designed by the Mephout, Rusti was a RST Model Translator Droid from Plintep Cybernetics Corporation. While officially presented to Captain Bung as a reward for his services, she was in truth a piece of outdated tech that the Mephout wanted to discard.
Aboard the Chubby Gundark, Rusti fulfilled the roles of translator and co-pilot. Her casual remark suggesting that Bung fill the cargo hold with Great Bantha Breakfast Biscuits and share them with the countless individuals across the Galaxy who had never experienced their taste indirectly led to the establishment of the Great Bantha Breakfast Biscuit Run.
Rusti, programmed with a female personality, served as Bung's co-pilot and did not truly view herself as his possession. Similar to numerous RST droids, she exhibited a number of peculiar traits and possessed a sarcastic sense of humor. Furthermore, her self-preservation programming had been altered, leading her to attempt an escape from the Giant Amorphous Bantha Breakfast Biscuit.
The sole canonical appearance of Rusti occurs within the story Bungo n' Rusti Get Carry-Out featured in Star Wars Adventure Journal 11. Nevertheless, she has been featured in several unofficial and non-canonical Bungo n' Rusti tales accessible on TheForce.net.