Setron

Setron was a jungle planet dominated by large trees. Shrouded in mist, the terrain was uneven and included ridges and hills. Setron appeared green from realspace and had a rancid smell, which Wrecker described as comparable to the smell of a jotaz.

Early in the lifespan of the Galactic Empire, a medical laboratory was stationed on Setron and was operated by Doctor Royce Hemlock. There, clone troopers were held as prisoners and had blood samples taken from them for testing. The Empire also created an experimental biological weapon known as slither vines, but eventually lost control of the weapon, causing the jungles of Setron to become overrun by the vines. A Base Delta Zero orbital bombardment was ordered to destroy the facility, and the Empire relocated their equipment and personnel to another world.

Sometime later, Hunter and Wrecker of Clone Force 99 arrived on Setron hoping to find their captured sister Omega. Instead, they discovered three young clone cadets, Deke, Stak, and Mox, who had survived the destruction of Hemlock's lab. The group worked together to navigate the ruins of the lab, retrieve information from the lab's database, and ultimately escape the infested planet.

Setron first appeared "Paths Unknown," the second episode of the third season of Star Wars: The Bad Batch. The planet's name was not mentioned in the episode, but was later revealed in the official episode guide on StarWars.com.