He is a Dug podracer and is the young Anakin Skywalker's arch-rival. Originally hailing from Malastare, he was a former slave who had bought his freedom with his incredible skills at podracing. Before long, Sebulba became the star racer of the Galactic Podracing Circuit, based not only on his formidable racing skills but also his penchant for violence. Many fellow podracers were killed or injured by Sebulba's reckless steering or out-and-out cheating, but Sebulba was far too popular to be blamed or penalized. According to junk dealer Watto, Sebulba won every race he participated in, usually by cheating.
Sebulba is first encountered by Jar-Jar Binks after Jar-Jar accidently spit a Gorg at him. Sebulba attacks Jar-Jar, but it's stopped by Anakin. The Dug is a participant in the Boonta Eve Podrace, and is the obvious candidate to win. He secretly sabotages part of Anakin's pod, which causes one of the turbines in Anakin's pod to overheat and almost burn out later in the race.
In the first lap, he destroyed Mawhonic's podracer in the first stretch of the course. In the second lap, he used an illegal flamethrower mounted on his Plug-F Mammoth to roast Clegg Holdfast's engines, destroying his pod. He also ditched a piece of iron into Mars Guo's giant engine turbines, blowing it up. In addition, he also was targetted by fellow racer Ratts Tyerell for death in large part due to his cheating methods, although Tyerell never got the opportunity to kill him, ending up killed in the Laguna Cave during the second lap.
However, during the last lap, Skywalker caught up with him. After a few attempts to ram his podracer into Anakin's to knock him off course, their pods tangled with each other. Anakin boosted his engines, sending Sebulba's left engine flying. It hit a rock, went spinning, and then burst into three flaming pieces. His right engine was devastated when it hit the ground and exploded. Sebulba did survive; in fact, he wasn't even physically injured, exclaiming 'Poodoo!' in frustration over his defeat. The loss was a temporary blow to Sebulba's reputation and ego.
Sebulba recovered quickly: purchasing Anakin's podracer from Qui-Gon Jinn, he showed up his rivals at the Vinta Harvest Classic and the Phoebos Memorial Run race on his home planet of Malastare the following season. Sebulba went on to win many more races, with his brutal competitive edge.
At some point at 32 BBY Sebulba had learned that a Dug called Gazurga had bet against him in the Boonta Eve Classic podrace. Sebulba considered Gazurga a traitor and posted a bounty on him of 4,000 credits. This bounty was claimed by Jango Fett.
Sebulba, after a while, took a rest and quit podracing. His son, Hekula, was allowed to fly Sebulba's podracer (the one he bought from Qui-Gon) six years after the Boonta Eve Classic, also being beat by Anakin. Hekula, however, was a rookie, and he smashed the podracer in his debut race. Sebulba then purchased a Plug-F Gargantuan, a remake of his famous podracer that crashed in the Boonta Eve Classic. After purchasing the pod, Sebulba forbade Hekula from podracing, never letting him near any podracer and podrace again.
Eight years after Anakin Skywalker had won the Boonta Eve Classic, Sebulba wanted revenge and challenged Anakin one last time to race on his home turf once more, with his newly acquired Gargantuan. After Anakin salvaged parts of his podracer that Hekula crashed, he entered the race. But the results of the race are unknown.
Though Sebulba eventually met a fatal end (much to the joy of those whose enmity he had earned), his legacy survived into the Imperial Era, where a grandson of his named Pugwis continued the podracing tradition, winning frequently because of his skills inherited not from his father, Hekula, but his grandfather, Sebulba. He also used his pod-racer in Jabba the Hutt's demolition games.