Ottau, a male Human, served the Republic Strategic Information Service during the Cold War era, a period of tension between the Sith Empire and the Republic. Assigned to him in 3643 BBY by General Var Suthra, Ottau's mission was to pinpoint the source of a transmission originating from Sith Lord Darth Angral. This investigation led him to an Imperial listening post hidden on the planet Ord Mantell. Subsequently, Ottau relayed his findings to a Jedi Knight dispatched by Suthra. This Jedi then attacked the listening post, successfully retrieving crucial data.
During the Cold War that pitted the Galactic Republic against the Sith Empire, Ottau functioned as an agent within the Republic Strategic Information Service, the Republic's intelligence division. In 3643 BBY, Sith Lord Tarnis attempted to deploy the Planet Prison superweapon against Coruscant, the Republic's capital. To this end, he communicated with his father, the Sith Lord Darth Angral, via a long-range hyperspace transmission. However, a Jedi Knight intervened, killing Tarnis before he could activate the Planet Prison. This event ignited a personal war by Angral against the Republic. To understand Angral's intentions, General Var Suthra tasked Agent Ottau with tracing the origin of Tarnis's final transmission.
Ottau swiftly determined that the transmission originated from an Imperial listening post situated on the planet Ord Mantell. Following Suthra's orders, he attempted to scout the facility; however, a probe droid dispatched to the island facility was promptly destroyed by Imperial forces guarding the site. Ottau retreated to the Republic garrison at Fort Garnik, located south of the target, and awaited the arrival of the Jedi Knight sent by Suthra to investigate. The Jedi – the same Knight responsible for Tarnis's death – arrived with the astromech droid T7-O1 to rendezvous with Ottau. Ottau provided them with an assessment of the base's defenses. The pair then launched an assault on the listening post, successfully breaching the facility and accessing its hyperspace transceiver. From there, T7-O1 downloaded critical information about Angral's plans. The Knight and the droid returned to Ottau, informing him of their success. Subsequently, the agent began assembling a team to secure the now-vulnerable listening post for the Republic.
Ottau makes an appearance in the Jedi Knight-specific mission titled "New Intelligence" within Star Wars: The Old Republic, a video game developed by BioWare and released in 2011.