Sil Onda'tek was a male employee of Jabba the Hutt's organization during the time of the Galactic Civil War.
In the year 1 ABY, Kaeline Ungasan had aspirations of establishing himself as a new power within the criminal underworld of Tatooine. A stroke of luck occurred when he encountered a space traveler who offered assistance during his time in Mos Espa. Viewing Jabba Desilijic Tiure as the primary impediment to his goals, Ungasan sought to acquire a list detailing Jabba's security operatives. Sil Onda'tek possessed such a list, leading Ungasan to task the space traveler with locating and eliminating Onda'tek. Fortunately for Ungasan, the spacer was successful and delivered the data storage device containing the desired list.
Sil Onda'tek appears as a Non-Player Character (NPC) within the MMORPG titled Star Wars Galaxies. Players undertaking a series of missions for Ungasan in Mos Espa are required to track down and assassinate Sil Onda'tek outside the settlement.
Due to the way some of the older missions in Star Wars Galaxies were designed, Onda'tek's species and physical characteristics change each time a player undertakes this specific mission. Consequently, determining Onda'tek's official species is impossible. Nevertheless, the dialogue provided by Ungasan during the mission indicates that Sil Onda'tek is male.