Once Bitten is the customized weapon of Baryos Nitran. It was originally the Vanguard gun Up For Anything, belonging to Sauron-145. After his death at the hands of a Hive Knight, it was given to Baryos as part of Sauron's will. It has been modified significantly.
Once Bitten has the model of Up For Anything. However, it has several deviations. The typical iron sight has been replaced by a Ranged Lens RLS3. Instead of the orange theme and Vanguard logo, the side of the weapon is painted black and adorned with the Warlock Rune of the Disciple. The ammunition counter has been replaced and glows a bright lavender, as the weapon has been infused with Void Light. The vertical foregrip is composed of a piece of Quite Content Damsel, a ship Baryos previously owned, and crashed during the events on Ceres.