Lego Raptor2' moves like a dinosaur by swinging it's head while walking like a real biped. The tail swings freely absorbing side to side torque. Steering is controlled by a small change of speed altering the bounce of an imbalanced gate. This basic leg design is what I used in Big Dog4.<br /> See more about getting biped feet in the air in the first video<br />Lego Raptor1: <a href="https://youtu.be/Y-TmDSCBgX8" target="_blank" rel="nofollow">https://youtu.be/Y-TmDSCBgX8</a><br />...<br /><a href="https://www.youtube.com/watch?v=dZIsDstTSUE" target="_blank" rel="nofollow">https://www.youtube.com/watch?v=dZIsDstTSUE</a>