We will use a 555 IC to simulate blinking eyes. The 555 will allow the eyes to glow for a few seconds, then blink off for a fraction of a second. Cut eyes out of a toilet paper tube, put the circuit inside, and hide them in the bushes for Halloween!
A description of the various pins on the 555 can be found here.
To ease calculation of the period, frequency, and duty cycle of a 555 circuit, you can use an online calculator.
You can see video of the spooky eyes in action here.