TX-20 was a commander serving the Confederacy of Independent Systems during the Clone Wars. This T-series military strategic analysis and tactics droid was under the command of Wat Tambor, who held the positions of foreman within the Techno Union and Emir of Ryloth.
During the Battle of Ryloth, TX-20 and his forces successfully seized control of Nabat, a city inhabited by the Twi'lek species. They then set up a fortified base within the city's central courtyard and took the local population captive. TX-20's mission was to prevent the Republic from liberating Ryloth. To achieve this, he used the captured Twi'leks of Nabat as human shields, hoping to deter the Republic from launching any retaliatory attacks against his droid forces.
As part of Techno Union Emir Wat Tambor's occupation force, TX-20, a masculine tactical droid, was deployed to the planet of Ryloth and led the conquest of the city known as Nabat. In that location, the droid took on the role of commander, establishing a base camp, which included a Separatist command center, in the city's courtyard. TX-20 defended the site with five proton cannons, and captured the remaining citizens of Nabat, using them as a shield to protect his cannons.
After the blockade was destroyed, Tambor contacted TX-20, instructing him to stop the Galactic Republic forces from landing their troops. The droid commander initiated cannon fire at the Republic transports and gunships; however, the gunships managed to land successfully. He dispatched recon droids to gather information about the Republic's attack strategy and then commanded his droids to unleash the starving gutkurrs—predatory insect carnivores—upon the clones. Although Kenobi managed to defeat the creatures, TX-20 observed that the Techno Union's forces were dwindling.
The tactical droid made preparations for a final offensive, assuring Tambor that the clones had little chance of success. TX-20 commanded his tanks and droids in an assault against Clone Commander Cody's troops. However, one of his battle droids informed him that Kenobi was in the process of freeing the Twi'lek prisoners—the native inhabitants of Ryloth. He then redirected his AAT tank to confront Kenobi, firing upon the Jedi General and destroying the remaining proton cannon. TX-20 held Kenobi and the Twi'lek youngling Numa at gunpoint, expressing his belief that victory was assured. However, he had failed to account for the morale of the prisoners, who were inspired by Numa's bravery and overwhelmed his tank, leading to his destruction.