Unit 26, also known as Unit 2-6, was a BX-series droid commando who participated in the takeover of Rishi Station during the Clone Wars along with other commando droids, such as Unit 07.
In 22 BBY, Unit 26 and other Separatist BX-series droid commandos were tasked with infiltrating the Galactic Republic Rishi Station on the Rishi Moon and activate the "all-clear" signal, allowing for a surprise attack on the key Republic world of Kamino. Unit 26 and the other droids used Droch-class boarding ships and a meteor shower to land near the base. After sneaking in and killing several clone troopers, the droids hard-wired the "all-clear" signal, despite several clones managing to escape.
Clone Captain CT-7567 "Rex" and Clone Commander CC-2224 "Cody" arrived for a standard inspection, Unit 26 disguised itself as a clone, and approached them in an effort to cancel the inspection. When Rex and Cody were alerted by a droid attack flare, Rex shot and destroyed the disguised Unit 26. Although Cody was shocked, Rex quickly relieved him when he took of the clone helmet, revealing Unit 26's faceplate. At that time, they were ambushed and driven off the platform, with the Separatist droids believing that they were pulverized. Afterwards, Unit 07, 08, and 09 guarded the entrance to the base when Rex tricked Unit 07 into opening the doors for Unit 26. When the doors opened, Unit 07 and the other droids were destroyed, and the clones succeeded in recapturing the base, but not before a fleet of Separatist warships arrived overhead and deployed reinforcements to retake the base.
Unit 26 debuted in "Rookies," a 2008 episode of the first season of the TV-series Star Wars: The Clone Wars.