Last year on Halloween, "Glowy Zoey" the LED light baby toddled into our hearts and basically stole Halloween from all babies everywhere. And now this glowing cherub has returned, and she can talk! *Clutches chest* The cuteness, it's overwhelming!

From her parents via their YouTube page:

After last year's costume went absolutely nuts, I had to make a new one that was much, much better. The 2014 version is using digitally addressable LED strips hooked up to an Arduino microcontroller which I programmed (and still learning). It is responsive to sound and has 2 potentiometers and a button in the back of one of the ears for control and a microphone hidden in the front. It has 12 modes and 372 LEDs (124 chips with 3 each).

And yes, they are selling baby halloween costumes.