Tigris was a male Firrerreo from legends, born to Hethrir and Rillao.
At the time of Tigris's conception, the Sith Lord known as Darth Vader envisioned turning the child to the dark side of the Force. However, Rillao had different plans and absconded with Tigris (who, incidentally, possessed no Force abilities). Hethrir eventually located them, torturing Rillao and forcing Tigris into servitude.
Hethrir, having risen to the position of Procurator of Justice, escaped to a self-made planet, a Worldcraft, accompanied by his followers, including Tigris. Hethrir's ambition was to become the new Emperor through his Empire Reborn movement. To achieve this, he sought counsel from Waru, a grotesque, extradimensional, Force-sensitive being of flesh who purported to be a healer (but in reality, drained the life force of his victims in an attempt to open a portal back to his own dimension). Waru resided on Crseih Station.
Despite being relegated to the menial role of a nursemaid, Tigris remained devoted to Hethrir, serving him to the best of his ability. Hethrir also indoctrinated Tigris with the belief that his mother, Rillao, was a traitor who had robbed him of any Force potential. Unlike Hethrir's other adherents, such as the Helpers and Proctors, Tigris showed kindness towards the children held captive on the Worldcraft. Furthermore, Tigris was undersized for his age due to a lack of proper nutrition.
In 14 ABY, around the age of twelve or thirteen, Hethrir abducted the children of Leia Organa Solo and Han Solo, who were the Chief of State of the New Republic. The Solo twins, Jacen and Jaina, were integrated into groups with other children and placed under the authority of older children known as Proctors. However, their younger brother, Anakin, was intended as a sacrifice to Waru in exchange for Hethrir's ambitions being fulfilled.
During this period, Tigris was assigned to care for Anakin. Developing empathy for the three-year-old boy who had been separated from his family, Tigris grew fond of Anakin and made a conscious effort to provide him with food and care. When Hethrir departed for Crseih Station to offer Anakin as a sacrifice to Waru, Tigris accompanied him. Later, at a park on Crseih Station, they encountered C-3PO, who attempted to rescue Anakin. However, Hethrir intervened and deactivated the droid.
Subsequently, as Hethrir prepared to sacrifice Anakin to Waru, Tigris experienced a change of heart. He turned against his master, rescuing Anakin from Waru just before the sacrifice could be completed. Enraged, Hethrir attempted to punish Tigris, but he was interrupted by the arrival of Leia, Han, Jedi Master Luke Skywalker, and Rillao, who had formed a bond with Leia. Ultimately, Waru, having abandoned all hope of creating the portal back to his galaxy, pulled Hethrir into his energy field, resulting in their mutual destruction. Mother and son were then reunited, and Tigris, accepting the reality that he possessed no Force potential, chose to rebuild their relationship.