LEGO MINDSTORMS Robot Inventor
This T-Rex robot dinosaur walks on two feet, opens and closes its mouth to roar, and waves its tail back and forth!
You can control the T-Rex with either of two remote control programs provided, or try the autonomous program for a quick demo of the motions, and modify it to make your own sequence.
The ankle mechanism in the legs makes the robot shift its weight from side to side as it walks, which enables walking on two legs without anything else for balance, which is not easy to do. I learned this mechanism from The LEGO MINDSTORMS Robot Inventor Activity Book.