Bossk was a male Trandoshan bounty hunter and the son of Cradossk who was known for hunting Wookiees. During the Clone Wars, Bossk worked alongside fellow hunters Aurra Sing and Castas to mentor the orphaned Boba Fett. Their scheme to kill Fett's hated enemy Mace Windu resulted in Fett and Bossk's arrest. After a stint in prison, Bossk worked in Fett's syndicate of bounty hunters, taking jobs for clients including Otua Blank and Asajj Ventress.
After the rise of the Empire, Bossk traveled to the Outer Rim planet of Lothal to collect a bounty on the Dug criminal Gronson Takkaro, who had jumped bail in the Ahakista system. During his Lothal trip, Bossk also joined forces with the Force-sensitive street urchin Ezra Bridger to stop the corrupt Imperial Security Bureau Lieutenant Jenkes. Following the Battle of Hoth, Bossk would be called upon by Darth Vader to find and capture the Millennium Falcon.