I bought this skull to decorate my computer desk. However, analyzing better, I could do something more interesting.
I hope you enjoy.

Step 1: Materials

- A plastic skull

- 8 screws;

- Microcontroller (I used an Arduino board);

- A Protoboard

- A nunchuck (for nintendo wii control) with a adaptador

Note: I bought the adapter but can be easily made by following this step by step: https://www.instructables.com/id/Wii-Nunchuck-Adapter/

- Mini servos (initially, I use 2. An eye and another to the jaw);

- Batteries (attached to the computer, use the power from usb);

- Drill, various drills, a metal rod of about 20cm, glue, bits of wire, etc ...

Step 2: Riding the Skull

If the skull comes disassembled (like mine), mount it by following the manufacturer's instructions.
i detachedthe teeth and fixed then on the jaw. Note: I tried to use the most of the stuff I bought. Then I used the disposable part where the teeth were fixed.
The brain was not used because in his place will be the servos and the microcontroller.

Step 3: Preparing Eyes

Inspired by Achmed the Dead Terrorist, jeff dunham´s puppet, I decided to make the eyes move only sideways. Thus, it would be easier to assemble. Just increase the hole is in the eye with the aid of a drill.

Step 4: Preparing the Skull

The skull has two holes where the eyes are to fit a screw. Take care to drill the more centralized as possible because his skull will get a bit cross-eyed. In the eyes, has a "beak" that i had put one screw. For the eyes move, two holes were opened with a drill so that the rods made with the screws behind the eyes to move from one place to another. That done, I made a guide to uniting these rods, temporarily with a popsicle stick. The result was very good.

Now just put the servomotor and make linking a guide to terms with the eye movements controlled.

Step 5: Preparing the Jaw

With the help of a smaller drill, drill a hole at the ends that fit into the skull to pass the wire that will control the movements of the mouth. The "springs" that made the mouth be closed also been removed. It has two "balls" on the ends that were also cut because it difficult to correct closing the mouth.

Step 6: Placing the Wire Jaw

The wire for the mandible was done following the steps of the figure. By placing the jaw in place it was found that the bite was not good. So, I used a drill to fix it. This done, the teeth fit together right.

Step 7: Placing Mandibular Servo

The servant was fixed to the skull with the help of two bolts. The rod was made with a piece of wire for aileron control. It could simply bend the wire, as I did on the rod to control eyes. After determining the limits of movement (mouth open and mouth closed), I glued the rod in the jaw with two drops of superglue. Then just stick the straw in the servo and wire the jaw.

Step 8: Putting the Servant of the Eye

To control the eyes, I used the plastic part where the teeth came to join them, making them both were moving in the same direction. It was enough to make the holes after the eye center. The rod I did with a piece of wire, and fixed according to the figure in the servant's eyes and the shaft. After checking the operation of the mechanical part, went to the algorithm to delimit the boundaries of the servant.
Servants working:

Step 9: Controlling the Servants

To control the movements of the skull, used as the "brain" an Arduino with the aid of a nunchuck.
To connect the nunchuck to the Arduino, I used an adapter.
Connections are very simple. Servants were connected to pins 8 and 9, with the help of a breadboard. The power comes from the Arduino when it is connected via USB or a set of batteries when not in PC.
The software, I got on the inside and adapted to the skull.
For more information, see:
http://todbot.com/blog/2008/02/18/wiichuck-wii-nunchuck-adapter-available/

Special thanks to:
https://www.instructables.com/member/oomlout/
https://www.instructables.com/member/dany32412/
https://www.instructables.com/member/josestude/

For they have helped me with their Instructables, using the nunchuck with Arduino.