L4-B5 was an astromech droid that belonged to Sergeant Pell of Republic Army's Fifth Squadron during the Galactic War between the Galactic Republic and the Sith Empire. In 3641 BBY, the droid and Pell crashed in the Flatlands regions of Ilum, and L4-B5 raced back to the Republic base camp to plea for help for its master from Republic aligned individuals.