K-2SO, also known as Kay-Tuesso, is a reprogrammed Imperial security droid featured in the film 'Rogue One: A Star Wars Story.' Originally an enforcer droid in the Galactic Empire, K-2SO was reprogrammed to serve the Rebel Alliance. With a sharp wit and a penchant for sarcasm, he provides both comic relief and essential support to the main characters during their mission to steal the Death Star plans. K-2SO is known for his loyalty and bravery, often putting himself in harm's way to protect his friends.