Tuz was a tall, overweight Mon Calamari pirate and trader who operated during the reign of Emperor Palpatine. Tuz did not initially get involved in the Galactic Civil War, but he was reluctantly drawn into service to the Alliance to Restore the Republic as a result of pressure applied by the Rebel Admiral Gial Ackbar. Under the supervision of Vice Admiral Wirriz and Commander Fortune, Tuz participated in undercover missions against the Galactic Empire and supplied the Rebels with what he stole. Shortly before the Battle of Yavin, Tuz helped deliver some Imperial equipment from the stolen BFF-1 bulk freighter Sidral II to the Mon Calamari Star Cruiser Independence, which Alliance High Command hoped would lead back to contractors working on the Empire's Death Star battlestation.