Via USAtoday.com:

Sometimes it isn’t easy being a Star Wars droid, even a scene-stealing one.

The former Imperial robot-turned-hero K-2SO was played via performance capture by Alan Tudyk in Rogue One: A Star Wars Story (available on digital HD platforms Friday, Blu-ray/DVD April 4) and joins the likes of C-3PO, R2-D2 and BB-8 as mechanical characters who’ve taken Star Wars fandom by storm.

To play the 7-foot-tall and very snarky Kaytoo, Tudyk would don 13-inch stilts while filming scenes for the movie, which centers on the robot and his Rebel buddies such as Jyn Erso (Felicity Jones) and Cassian Andor (Diego Luna) stealing the plans for the Empire’s super-weapon, the Death Star. But as revealed in the above exclusive behind-the-scenes clip, there were some scenes too awkward or dangerous for Tudyk to film while on stilts. In those instances, he wore a backpack rigged with a couple of poles and a cutout Kaytoo head to keep his eyeline in place.

“If there’s ever a time where I have to put that thing on (I thought), ‘Oh God, no, here it comes.’ It’s so awful,” says Tudyk, who was not that impressed by the “really rudimentary” piece of poster board that stood in for Kaytoo’s face. “Diego said, ‘Alan, it’s amazing how little respect you have on set right now.'”

Another fun fact: K-2SO was originally supposed to be a black protocol droid along the lines of C-3PO. The exclusive below video on Rogue One easter eggs discusses that and other cool Star Wars connections such as the droid that was a practical puppet designed by the folks who created BB-8, a turbo tank last seen in Episode III: Revenge of the Sith, and the first appearance of a TIE Reaper, a new twist on the iconic Imperial TIE Fighter.