Warto was a male Boltrunian of the Cloud-Riders, serving under Serji-X Arrogantus. Initially, he toiled as a laborer aboard a Corellian freighter, but his temperament and behavior frustrated his fellow crew members. Consequently, they abandoned him on Aduba-3, forcing him to scrape together a living by lifting crates and strongboxes at the local starport, supplemented by mugging weaker inhabitants. He frequented Locru's Central Saloon, indulging in copious amounts of potent nikta.
One evening, Warto mistakenly believed that the Wroonian Azoora was his girlfriend and became incensed upon witnessing Han Solo, a Corellian pilot, attempting to court her. A fight ensued, during which Warto was overpowered by Solo's first mate, the massive Wookiee Chewbacca. Humiliated, Warto later sought to join a group being formed in Tun Aduban to earn enough credits to leave the planet, but his attempt was thwarted by the irritated Lepi, Jaxxon. Upon discovering that Solo was assembling the posse, Warto aligned himself with Serji-X Arrogantus and the Cloud-Riders, who were terrorizing a nearby village. The Boltrunian informed Arrogantus about Solo's posse and subsequently participated in the Cloud-Riders' raid on the village of Onacra. During the conflict with Solo's posse, Chewbacca crushed Warto to death.
During the Imperial Period, Warto, a green-skinned Boltrunian, secured employment as a laborer on a Corellian freighter. His volatile temper made him unpopular, leading his fellow crew members to abandon him on the isolated world of Aduba-3. Consequently, Warto harbored resentment towards all Corellians. He eked out a meager existence by preying on weaker individuals through muggings. He also worked as a spaceport crater-buster, hauling strongboxes for those unable to afford a binary load lifter.
Warto spent much of his time at Locru's Central Saloon in Tun Aduban, developing a fondness for strong nikta. One evening in 0 ABY, Warto deluded himself into believing that the attractive and flirtatious Wroonian, Azoora, was his girlfriend. He became enraged when Han Solo, a Corellian smuggler, appeared to be attempting to seduce her, and seized him. Warto threatened the Corellian, warning him to stay away from Azoora. Solo feigned innocence and advised the Boltrunian to leave before his Wookiee co-pilot, Chewbacca, arrived. Warto scoffed at the threat, prompting Solo to smash a chair into the Boltrunian's face. Enraged, Warto lifted the Corellian and threw him across the bar. A brawl erupted before Chewbacca's arrival. Undeterred, Warto struck the Wookiee several times, but Chewbacca seemed unaffected. Subsequently, Warto was hurled through a plate-glass window.
When rumors circulated about a posse being formed for an undisclosed purpose, Warto attempted to enlist, viewing it as a chance to earn enough credits to leave Aduba-3. The posse organizer was interviewing candidates at Locru's inn, where a queue had formed. As the Lepi spacer Jaxxon prepared to enter the interview, Warto cut in front of him. The Lepi protested, and Warto responded with a strike. Angered, Jaxxon retaliated with a powerful kick, preventing Warto from joining the posse. Warto later learned that Solo himself was assembling the posse to defend the innocent farmers of Onacra village from Serji-X Arrogantus and his Cloud-Riders.
Warto chose to join Arrogantus instead, informing him of Solo's activities. Arrogantus was impressed by the Boltrunian's strength and fury, granting him a skyspeeder previously owned by a victim of a high-hound. Warto shared information about Solo's actions, and the Cloud-Riders returned to Tun Aduban, encountering the newly formed posse, the Star-Hoppers of Aduba-3. When Solo noticed Warto among the Cloud-Riders, the Boltrunian taunted him, but Arrogantus forbade Warto from firing until instructed. Arrogantus and Solo exchanged words before the Cloud-Riders departed to prepare for their next attack on Onacra.
Warto later participated in Arrogantus's attack on Onacra. Observing that the Star-Hoppers had ignored Arrogantus's earlier warning, Warto resolved to show no mercy to the defenders. However, the telescoping arms of one defender, FE-9Q, seized his skyspeeder, bringing it to a halt. Chewbacca dismounted Warto and then killed him with his bare hands. Voren Na'al, a historian, later profiled Warto, adding his biography to the Alliance to Restore the Republic database, Mistress Mnemos.
Warto was known for his exceptionally short fuse and limited intelligence. His disposition was so unpleasant that it prompted his crewmates to abandon him on the desolate Aduba-3. To survive, Warto chose to exploit those weaker than himself. The Boltrunian was also a heavy drinker, capable of convincing himself that Azoora was his girlfriend—his self-deception was so complete that he became highly aggressive when a smuggler, especially a Corellian, approached her. Warto was also impatient, cutting in line to join Solo's posse.
His primary goal was to escape Aduba-3, which motivated most of his actions. He was driven by vengeance, which ultimately led Serji-X Arrogantus to employ him. The Boltrunian developed a hatred for Solo and was eager to shoot him down, but he had to obey his new master. Warto also held a disdain for the Lepi, Jaxxon, calling him a "rodent" and provoking a strong reaction from the spacer. While he considered Solo a relatively easy physical opponent, Warto was no match for Chewbacca, whose strength he had initially dismissed. Warto possessed skills in speaking, reading, and writing Basic. He also carried a blaster pistol.
Roy Thomas, Howard Chaykin, and Tom Palmer created Warto for Star Wars (1977) 8 (1978). The character met his end in the subsequent issue, Star Wars (1977) 9 (1978). He was later profiled in The Starhoppers of Aduba-3, featured in Star Wars Gamer 4 (2001).