During the Clone Wars, Thill accompanied Jedi Generals Obi-Wan Kenobi and Anakin Skywalker on a mission to the planet Felucia, and on arrival near the world, Thill detected a transmission from a Separatist base on the world that revealed that the Separatists were about to fire on the Jedi light cruiser. Thill and the two Jedi transferred to a smaller vessel moments before the Separatists destroyed their transport, and they headed to the planet's surface. Intending to destroy the Separatist installation, the trio trekked through the Felucian jungles in the direction of the base, and a light on Thill's helmet attracted wild creatures, which attacked the clone.
After defeating the creatures, the trio resumed their mission, and on arrival at the base they affixed several homing transmitters to the structure, so as to enable a Republic fleet to fire on the facility. However, after setting up the transmitters, Thill and the Jedi encountered a band of abandoned children who lived in the vicinity of the base. To avoid the children coming to harm from the Republic bombardment, the trio took the children back with them to their transport, and when they arrived at the ship Thill gave the Felucian child Kralla his trooper torch, claiming that it was lucky. Moments later, the transport fell under attack from a squad of Separatist battle droids, who attempted to prevent it from taking off. Disobeying a direct order from Kenobi, Thill jumped down from the vessel to hold back the droids while the Jedi and the children escaped aboard the ship. Thill then perished during the subsequent bombardment of the Separatist base.