Tod Kurt has been doing a wonderful series of tutorials to help you learn CircuitPython. Of course, being October, he’s chosen a spooky theme.
If you’ve ever wanted to know how to do a 2 axis gimbal, this simple little eyeball project will give you all you need to know, in order to make it work on an Adafruit QT Py.
Another fantastic example is this fire effect. It is truly amazing how such a convincing effect can be created so simply. The diffusion’s importance can’t be understated though, you can see in this Gif that it makes a world of difference.
Probably the creepiest of them all is this simple LCD eyes animation. This could easily be squeezed into some fun costume ideas as well.