"Doctor Ball" was an IT-O Interrogation Unit in service to the Galactic Empire before the start of the Galactic Civil War. Grand Moff Wilhuff Tarkin and Imperial Security Bureau Agent Kallus used Doctor Ball to inject truth serum into the Jedi Kanan Jarrus aboard Tarkin's Imperial I-class Star Destroyer, the Sovereign. The Imperials hoped to procure information from Jarrus, but the Jedi was able to resist giving away any information under Ball's injection. Having grown tired of Ball's inability to break Jarrus, Tarkin had the Grand Inquisitor take over the interrogation.
Doctor Ball appears to be named after an IT-O unit of the same name, portrayed by Seth MacFarlane, who starred in a Robot Chicken: Star Wars Episode II parody sketch.