Xerius Ugg was a Besalisk commander of male gender, who fought for the Confederacy of Independent Systems.
On Kiros, Xerius Ugg commanded the droid army, devising a scheme to ensnare the Republic force sent to free the planet. Despite suffering heavy losses, he insisted on meeting with Jedi General Obi-Wan Kenobi to negotiate the surrender of his forces, revealing the placement of thermal explosives throughout the capital. Obi-Wan attempted diplomacy, delaying surrender until the safety of the Togruta population could be assured. However, Ugg's impatience led to an aggressive physical confrontation. While he battled Kenobi, Anakin Skywalker and Ahsoka Tano worked to disarm the explosives. A droid informed him of their progress, leading to a desperate attempt to detonate the bombs, but only one exploded—destroying his escape vessel. Kenobi used this distraction to knock him from the command center's height. At the base, Kenobi again pressed him for the location of the Togruta, but Ugg refused to divulge the information before his death.
It wasn't until the publication of the second issue of Slaves of the Republic that Ugg's first name, Xerius, was revealed.
The Battle of Kiros was depicted in animated form in the Clone Wars animated series episode Kidnapped from season four, but with significant alterations, most notably the substitution of Ugg with Darts D'Nar, a Zygerrian CIS commander.