See here an amazing example make from adam.fourney:
"Murray" looks like following you with his eyes and head. See in the Animation bellow (it takes some seconds to load). The whole thing is a pretty simple principle but looks impressive. The skull can be fixed on the wall like a picture or be placed somewhere on a Desk.
I made also a stand with the possibility to illuminate the skull directly by a LED, this amplifies the effect immensely.
Scale both models to the desired size and print easily (printing the skull upright will probably give the better results)