BT-1, also referred to as "Bee Tee," was a homicidal BT-1 assassin droid created by the Galactic Empire's Tarkin Initiative. After being found and reactivated by Doctor Aphra, BT-1 and his fellow droid 0-0-0 served under Lord Vader, and when Aphra faked her own death, he and 0-0-0 continued to roam the galaxy with her.