1. K-2SO is voiced and motion-captured by Firefly’s Alan Tudyk. Also goes by Kaytoo to allies and friends.
2. K-2SO is 7ft - 1 inch tall and previously was a security droid, enforcer and guard for the empire. (hence the size and demeanor) He’s since been reprogrammed to be a sidekick to Rebel captain Cassian Andor, played by Diego Luna.
3. The character also has an English accent, because Tudyk saw that as a big difference between the Empire and Rebellion. “I feel like a lot of the Imperial characters are English, and the Rebels tended to be like Han Solo, you think of the Americans,” Tudyk told EW. “And because he was a droid, it made sense that it would be more of a proper accent.”
4. He says insulting things very casually although the droid doesn’t really feel or exhibit emotion, unlike some of his counterparts, Tudyk described K-25O as "unsettling at times", so if this droid will continue the tradition of comic relief, you can be sure that humor will be dry, and dark.
5. Kaytoo and Cassian have been inseparable for several years by the time Rogue One starts. “They’ve been around. They’ve been together for a while, a couple years,” Tudyk said. “He wants what Cassian wants. He loves Cassian, because he freed him. It’s also more paternal in that [Cassian] gave him life and took away the bonds of his programming.” says Tudyk.