Star Wars: Rogue One Sizzle Reel Breakdown - 33 Things You Must See
28. A Rival For C-3PO?
Unless he ends up getting a new body, this is not in fact Alan Tudyk's K-2SO. This is in fact the RA-7 insect droid that was first seen in A New Hope, which were otherwise known as Death Star Droids after they were adopted en masse by Imperial officers as their service droids.
Here's one from A New Hope..
K-2SO on the other hans looks far less shiny and weird...