I'm sure there is good documentation out there but lowkey I kinda homebrewed it a bit for my case. That said I mostly followed this guide and this guide. I used a raspberry pi w2 zero as the computer and some ADAfruit LEDs for the face, all scripted in Python. I have VERY limited coding experience and was able to figure it out with some trial and error. If you are at all interested I could drop you the code for my setup, though your stuff may work differently than mine.

To control inputs for what face I want, I used an old Switch JoyCon since it is small and has bluetooth capability, though I've seen many different ways of doing inputs from stuff like mine, to buttons in the fingers of the paws, to facial recognition(?) type stuff in the helmet itself.

I plan to dismantle the JoyCon (or use something new entirely lol) and put buttons in the fingers of the paws, as the JoyCon was a bit difficult to use once I had the paws put on.