AP-5 has a grumpy, pessimistic, irritable and cynical personality due to his exploitative treatment at the hands of his Imperial superiors. He greatly prided his service as an analyst droid during the Ryloth campaign and deeply resented being relegated to inventory work under the Galactic Empire. AP-5 has an antagonistic relationship with his Imperial captain, who had little regard for the droid and thought that he was merely destined for the scrap heap.
AP-5 found an unlikely friend in the form of Chopper, an astromech droid who is part of the Rebel Alliance. AP-5 gained Chopper's trust and friendship after he removed his restraining bolt; giving AP-5 the will to defy his master. Despite his friendship with Chopper, AP-5 can still be abrupt and condescending to his friend. This was evident when he berated Chopper for committing the "illogical act" of sacrificing his stolen ambulatory strut to repair him.
Despite having engaged with the Rebels for only a short time, AP-5 has already formed an attachment to them, as he seemed genuinely saddened to learn of Ahsoka Tano's apparent death.
- Master Analyst: As an analyst droid, AP-5 can estimate if his allies' tactical strategies are 70% or 100% effective.
- Knowledge: Due to his position former position as inventory droid for the Galactic Empire, AP-5 is aware of the Imperial fleet's movements and star charts. AP-5 used this knowledge to help the Rebel Alliance to find a safe haven on Atollon.
- He is voiced by Stephen Stanton, who also voiced Wilhuff Tarkin in Star Wars: The Clone Wars. He reprises his role as Wilhuff Tarkin in Rebels and also voiced old Obi-Wan Kenobi in Season 3.
- Stanton based his portrayal on the late British actor Alan Rickman.
- AP-5's droid model was previously seen in the Original Trilogy used by the Imperials on the Death Star.
- AP-5 is named after series producer "Athena Portillo". According to Dave Filoni, the "5" comes from the fact that Portillo is exactly five feet tall.