Looks rusty. This Limited Edition item is available for 250 MC starting on August 3, 2010 and gives 1 xp when bought. The description reads "Maybe you can make a metal suit?"
When clicked the hand twitches and punches upward. Then the normal hand goes in and a clamp hand comes out and moves about a few times before going back in and being replaced by the normal hand again. During this whole hand switching process the robot's eyes flash red and small sparks shoot out of the robot.