Nobot

"Nobot," also known as "Ghost Droid," was a 3PO-series protocol droid that constantly walked the streets of Mos Espa on the planet Tatooine. The droid wandered aimlessly across the deserts of Tatooine, and the only thing truly known about it was that it was a resilient unit—despite its travels, it would always find its way back to Mos Espa. The droid became the subject of several tales and anecdotes, most notably from the aging marketplace vendor Jira.

For two peggats, the old vendor would tell her story. Jira claimed that Nobot had witnessed the murder of a young pregnant woman, while some believed the 3PO unit was the killer. Apparently, Nobot would play an audio recording of the incident, featuring the young woman pleading for her life and screaming in horror as the deed was done.

Beyond that, rumors persisted, claiming that the droid was surrounded by evil spirits or the dark side of the Force. Repeated attempts to destroy Nobot failed, sometimes with unexplained adverse effects for the droid's antagonists. Jira's fellow vendors, listening to her repeated tellings of the story, would eventually develop their own versions while trying to compete with her.

Text and facts from the “Nobot/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.