Old One-Eye was a rancor distinguished by having only a single eye. He participated in an underground rancor fighting league located on Coruscant, the galactic capital planet, during the era of the Clone Wars. While pursuing the Separatist operative Raice Liq, the Jedi pair of Anakin Skywalker and Ahsoka Tano found themselves within the rancor arena, where Tano was compelled to engage Old One-Eye in combat. Skywalker ultimately diffused the situation by using the Force to calm Old One-Eye, thereby enabling the Jedi to utilize the rancor in the capture of their target.
During the Clone Wars, a galactic war fought between the Galactic Republic and the Confederacy of Independent Systems, Old One-Eye, a brown-skinned rancor, lived. Anakin Skywalker, a Jedi Knight, and his Padawan, Ahsoka Tano, went undercover at an illegal rancor fighting event featuring Old One-Eye. This event was situated on Coruscant, the galactic capital planet, approximately eighty kilometers from the Senate Building. Their mission was to apprehend Raice Liq, a Muun who was exploiting these fights to funnel Republic munitions data to the Separatists.
In the arena, Old One-Eye was matched against another rancor, with the odds heavily favoring Old One-Eye at six-to-one. During the confrontation, Tano was unexpectedly thrust into the arena and compelled to battle both Old One-Eye and the other rancor. Skywalker swiftly joined the fray. Despite the ineffectiveness of the Jedi lightsabers against the rancors' robust hides, Skywalker successfully used the Force to calm the creatures. Before summoning Captain Rex of the 501st Legion to dispatch transports and additional clone troopers for assistance in arresting the 200 law-breaking gamblers, Tano climbed atop Old One-Eye, while Skywalker mounted the other rancor, in pursuit of Liq. Following the arrival of the clones, the Jedi, riding the rancors, cornered and apprehended Liq.
Old One-Eye made an appearance in Prize Contender, a comic authored by Rik Hoskin and visually brought to life by Tanya Roberts. This comic was featured in the September 2010 issue of Star Wars Comic UK magazine.