BL-OX was a droid residing on the scrap planet called Zoh. On this world, BL-OX, along with other droids, followed the leadership of Jek-14. Soon after the Freemakers' arrival on Zoh, seeking Jek-14's assistance, a thankless droid known as N-3RO instigated a droid rebellion aimed at Jek-14 and the Freemakers. N-3RO managed to persuade the other droids, BL-OX included, that humans were not to be relied upon. Their efforts were unsuccessful, leaving N-3RO still on Zoh, now equipped with a restraining bolt.
Bl-OX's initial appearance was in LEGO Star Wars: The Freemaker Adventures, but he was subsequently canonized within Star Wars: Droidography.