W1-LE was the "galactic entrepreneur" Lando Calrissian’s personal attendant droid, whom he had owned since the time of the Clone Wars. The droid once had a different body type but his master transferred his logic unit into the an RQ protocol droid at some point prior to the Siege of Lothal. Willie maintained Calrissian's farm on the Outer Rim world of Lothal when he was not present, performing such tasks as walking Calrissian's puffer pig, which he had acquired to begin an illegal mining operation on the planet.
During the Siege of Lothal, Willie, under the instructions of Calrissian, helped the Lothal rebels to escape the Imperial blockade around Lothal in return for giving him three of their stolen shield generators. The rebels traveled to Calrissian's farm in a stolen Imperial shuttle to rendezvous with W1-LE, who would assist them. With the aid of the Mandalorian rebel Sabine Wren, W1-LE created sensor buoys that would replicate the signal of the shuttle and scatter Imperial forces when they tried to track them. This plan worked and the rebels escaped the Imperial blockade and rejoined the Phoenix rebel cell's fleet in deep space. Unknown to both Willie and the rebels, the Sith Lord Darth Vader had planted a tracking device aboard the shuttle and used it to assault the Phoenix rebel fleet.