The Axis droid leader was a K3 security droid, modified with new programming, that spearheaded the Vanguard Axis in the initial years of the Imperial Era. In the period spanning from 19 BBY to 18 BBY, it crossed paths with the Bad Batch when they brought a shipment of counterfeit chain code chips to the Axis Base space station. Following Omega's discovery that the Axis droids were involved in trafficking the Wookiee Padawan Gungi, and her subsequent attempt to liberate him, the Axis Leader stepped in, only to be shot by Hunter.
The initial glimpse of the Axis droid leader was presented in the second promotional video for the second season of Star Wars: The Bad Batch.