The BD series was a series of class three Nanny droids in use during the Old Republic era. Jedi Knight Kerra Holt encountered several of these in the stronghold of the Sith twins Dromika and Quillan on the planet Byllura. They were charged with taking care of the twins, as neither of them was capable of taking care of themselves. When the Jedi tried to reach the twins, the nanny droids tried to intervene. While they were unarmed, they used their bulky mass to hurl themselves at Holt, who disposed of them with both her lightsaber and her Force powers with considerable ease.