XR the Experimental Ranger is a minor protagonist in the Kingdom Hearts Unlimited Saga, making his debut in "A Year of Misery" as a member of Team Lightyear on assignment from Star Command to halt progress on the creation of the Moon of Kingdom Hearts.
He was originally designed by the LGM's as a possible partner for Buzz Lightyear because being a robot, he could be rebuilt if destroyed. Originally, he had a very absent personality, and was only programed to learn from Buzz. On his first mission with Buzz, to try to protect the LGM's Unimind from Zurg, he was destroyed by Warp Darkmatter. He was rebuilt by the LGM's, but since Zurg captured the Unimind, the LGMs' ability to rebuild him was inhibited, resulting in XR being rebuilt with a very human personality.