Decide how long you'd like your snakes.  Cut a piece of crin, a piece of light pipe and a piece of wire.  The wire should be slightly shorter than the other two pieces.

Tuck the ends of the crin inside itself so it won't ravel.  Slip the light pipe and the wire through the crin.  

Thread one end of the wire through the hole you drilled in your servo horn and crimp it tight.  It's a good idea to add some epoxy to this connection (not shown).

Bend the other end of the wire into a tight loop so it's less likely to stick out through the crin.

On the end of the light pipe opposite the servo, make a snake head out of hot glue.  It helps to do this on top of wax paper so the glue doesn't stick.  Add some gems for eyes.  This takes a little finesse, but it's easy to trim the goober snake heads off and try again.

Glue the end of the crin to the snake head while the glue is still tacky.

Try out your fit by pressing the servo horn onto the servo and pushing the light pipe into one of the holes.  Be sure the light pipe is long enough that your servo can turn freely.

Cut two of everything except the circle band (you just need one of those).  Trace the pattern onto 1/8" craft foam and cut the pieces out. 

Glue them together using contact cement.  The last piece goes in a circle around the crown of your head -- the electronics will sit on this, so we're just creating a flat surface for it.

Make sure it fits your head, and adjust if it doesn't.  You want it to fit pretty snugly.  

Once it fits, glue the electronics onto the top circle band with the power port facing back. 

Glue your battery case below it on the back of the skull cap.

I used an inexpensive dred lock wig to cover the skull cap and electronics.  I got a cheap wig that didn't have a lot of structure inside, which meant there were plenty of gaps in the wig cap to feed the servos through.  You can also cut slits in the wig cap if needed.

Screw the servo horns and snakes on above the wig.  Thread the light pipe coming from the snakes through the wig cap into the holes in the 3d printed case so they light up. 

Plug your battery in and give it a test run.