Bun-Dingo, an assassin droid, was employed by Governor Bisad Koong with the mission of sabotaging the Umboo Racing Team so that Koong could secure victory in the Drainsweeper race.
Following the obliteration of the New Umboo Lightstation, Bun-Dingo found himself aboard Governor Koong's vessel. Gaff, having left to report the supposed death of Mungo Baobab after Koong's stolen Cloudcraft was downed, instructed him to assume control of the ship. Soon after, Gaff realized that Mungo had survived the crash. Bun-Dingo suggested that Gaff inform Koong of this development, but Gaff declined. Instead, he opted to deal with Baobab himself, aiming to prevent the Governor from losing favor with Admiral Screed. Subsequently, the droid revealed that Auren Yomm, Koong's primary rival in The Roon Colonial Games, had rescued Baobab. The Kobok then declared his intent to eliminate her as well.
After Gaff's failed attempt at assassination, the Kobok dispatched Bun-Dingo to sabotage the Umboo Racing Team. Following a brief, one-sided encounter, he seized R2-D2's pet Mudman, instructing the smaller droid to leave him alone. Undeterred, R2 observed the droid disabling BIX and contaminating Gee Long's beverage with droid coolant. The assassin droid's final task was to compete against Auren Yomm in the Drainsweeper event. Before the race commenced, while Bun-Dingo was replenishing his tank with Turbo Coolant, R2 infiltrated his tent and retrieved his Mudman, inadvertently spilling an unknown substance into the assassin droid's coolant supply. During the race's third segment, the droid activated his coolant system, resulting in a malfunction. In a final attempt to strike Auren, he lost his footing and tumbled off his Rockhopper. He met his end upon impact with the drain's bottom, Gaff having previously manipulated the artificial gravity to ensure a fatal descent.