Uingali foar Marocsaa was a male Paccosh, identified as belonging to the Marocsaa subclan, and a member of the Paccosh species. He engaged in a meeting with Mitth'raw'nuruodo, a Senior Captain from the Chiss Ascendancy, alongside other Paccosh. As a representative of the Paccian Governance, Uingali possessed a fragment of the schematic for the Kilji picket cruiser named Hammer. When they initially encountered Thrawn at a mining station operated by the Paccosh, Uingali gifted Thrawn a treasured ring of his clan. This ring bore the image of a chimaera, which served as the emblem for the Marocsaa subclan. During their subsequent meeting, Uingali was in command of a starship that prominently displayed the chimaera symbol on its exterior. While Thrawn eventually returned the chimaera ring to Uingali, he would later adopt the chimaera as his own personal symbol.
Years after his initial encounter with Uingali, Thrawn rose to the rank of Grand Admiral within the Galactic Empire. During his service, Thrawn's flagship, the first model Imperial Star Destroyer, was named Chimaera, and it also displayed the image originating from Uingali's ring. Furthermore, many members of the Chimaera's crew wore a stylized depiction of a chimaera, either on their arms or pauldrons, as a symbol of their loyalty to Thrawn.
Following the collapse of the Galactic Empire, the HK-87s, Morgan Elsbeth's assassin droids, displayed the same stylized Chimaera symbol that the crew of the Chimaera had once worn on the sides of their heads.
At some point in time, refugees originating from the planet Sunrise, and under the leadership of the Magys, made their way to Rapacc. They were fleeing a violent civil war instigated by the Agbui and Haplif. When the Nikardun arrived to continue their pursuit of these refugees, Uingali made the choice to keep the refugees' presence secret from them. Nevertheless, the Nikardun remained and began a blockade and the subjugation of the Paccosh. When the refugees expressed their desire to travel to the Chiss Ascendancy in hopes of receiving assistance, Uingali allowed the population of two Paccian refugee vessels, which managed to bypass the Nikardun blockade by escaping the Rapacc box system through either Shadow Number One or Shadow Number Two. However, the relationship between the Paccosh and the refugees would decline over time.
After the Nikardun pursued a ship of unknown origin (the Chiss ship Vigilant) out of the Rapacc system, Uingali was dispatched with a Paccosh task force to an abandoned asteroid mining station to determine if its sensors had recorded any data about the ship. En route, the Paccosh task force noticed that the mining station's external lights had been activated by someone inside. Preparing for a potential conflict, Uingali sent a group of three Paccosh ahead to surround any intruders in the mining station's equipment bay. Upon reaching the equipment bay, Uingali and the Paccosh encountered two beings of an unknown species. After establishing Taarja as a common language, one of the Paccosh acted as a spokesperson. They identified themselves as Thrawn and Thalias, and Thrawn explained that their goal was to preserve the art of cultures that were unable to preserve it on their own. Despite the fact that the Nikardun would want the Chiss captured if they were aware of their presence, the Paccosh decided to let the Chiss leave peacefully after realizing that they could explain that the mining station's external lights were remote-activated. Before departing, Uingali gave Thrawn a double ring depicting a chimaera. He wanted Thrawn to keep it as part of his art preservation project, hoping that the Marocsaa subclan would not be forgotten if the Nikardun exterminated the Paccosh people. Thrawn accepted the gift with respect, and Uingali inclined his head toward him. Uingali did not speak directly to Thrawn and Thalias, but he understood Taarja.
Later, Uingali observed another ship of unknown origin (the Chiss ship Springhawk) engage in battle with and capture a Nikardun blockage frigate.
Following the defeat of General Yiv at the Vak Combine homeworld of Primea, the Nikardun engaged in a power struggle among themselves. This resulted in the majority of the Nikardun withdrawing from Rapacc, allowing the Paccosh to revolt and defeat them. The Paccosh were able to capture their own Nikardun frigate in the process, and they painted its underside with an image of a chimaera.
Several months later, the same unidentified ship that had previously seized a Nikardun frigate returned to Rapacc. Senior Captain Thrawn, representing the Chiss Ascendancy, introduced himself and his ship, the Springhawk. Apparently, Uingali did not recognize Thrawn's name from their encounter at the asteroid mining station. Uingali sought to test the Chiss, as accounts suggested they were capable of neutralizing their adversaries without causing destruction. Uingali dispatched a passenger shuttle and instructed the Chiss to disable it. Upon successfully doing so without causing any damage, Uingali inquired about the Chiss's purpose, and Thrawn explained that they intended to ensure the Nikardun blockading Rapacc had been defeated. He also intended to return the double ring that Uingali had given him on the asteroid mining station. Uingali, now recognizing Thrawn, invited the Chiss to the surface for discussions, specifically requesting Thalias's presence. At the Paccian capital city of Boropacc, Uingali engaged in conversation with Thrawn, Thalias, and Chiss Mid Captain Ufsa'mak'ro (Samakro). Uingali inquired whether the two refugee ships dispatched by the Paccosh had reached the Chiss Ascendancy, and Thrawn informed him of their fate. One of the refugee ships reached the edge of the Ascendancy before being destroyed by the Nikardun, while the other ship's hyperdrive malfunctioned, leading to the asphyxiation of its passengers. Uingali expressed sorrow that the Paccosh efforts were in vain, but Thalias encouraged him, stating that the arrival of the refugee ship in the Ascendancy was the spark that led to the defeat of the Nikardun. Uingali informed the Chiss about the refugees being sheltered by the Paccosh, explaining that the Magys wanted to kill herself and her people instead of returning to their world. Uingali, knowing that the refugees were a matriarchal society, hoped that Thalias would be able to talk the Magys out of doing this. He also explained that the Paccosh were not on good terms with the refugees, but he also explained that the Magys was interested in the Chiss' desire to preserve the artwork for species not able to preserve it themselves. Thalias expressed doubts in her diplomatic abilities, but Thrawn believed that he would be able to establish a connection with the Magys using their fondness for art. The group subsequently left to speak with the Magys, who, alongside her people, was residing in a city a small distance away from Boropacc.
Upon arriving at the location where the Magys was residing, Thrawn was rejected by the Magys, who only wanted to speak with Thalias. During their conversation, Thalias was able to convince the Magys to join her and the Springhawk on a mission to investigate the status of her world before she could make a decision on suicide. Uingali informed the Chiss that the Magys had to wait for nine of her months with no contact from her world before she could make that decision, and, according to conversions, the Chiss only had two Chiss weeks before that time period expired. The Chiss informed Uingali about the mission to the Magys's world and departed shortly thereafter. Seven hours later, another Chiss ship, the Grayshrike, commanded by Senior Captain Xodlak'in'daro (Lakinda), contacted Rapacc and informed them of her desire to reach Senior Captain Thrawn. Uingali informed Lakinda of Thrawn's mission to the refugees' world and the current status of these refugees.
Uingali foar Marocsaa made his debut in Thrawn Ascendancy: Chaos Rising, a novel within the Ascendancy Trilogy authored by Timothy Zahn.