Plug the Circuit Playground Express into a USB power supply or a battery pack with the JST battery port. The bat will power up and you'll see its wings start flapping, along with the NeoPixel comet animation.
There are a few parameters in the code that you can customize for different effects.
You can adjust the angle range (
max_range) of the wings and the number of degrees that the wings move each time (
degree_change) for different flapping effects.
You can change the color of the animation for the NeoPixels. You can also change the animation that shows on the NeoPixels. Check out the CircuitPython LED Animations guide to see the other options available in the library.