A face, not a box
The head is not generated from code. It was sculpted in Blender, eyes, nose, smile and one ear, and it clips onto the body's neck tongue.
Smendiłendi
Four servos. One grin.
A small printed robot dog. Hobby servos, an ESP32, a touch sensor on its back, and a head sculpted by hand.
Pet it
A capacitive pad under the cap on its back knows when a hand is there. That is the whole input.
It waddles
Four servos, one per leg, no knees. Diagonal pairs swing together and the body rocks. That is the walk, and it stays.