How is procedural Generated Animation (PGA) using procedural programming techniques, as used in Games industry, different form Physics or Dynamics based Animation techniques for biped or quadruped locomotion?
A procedural animation is any animation controlled by programmer goal, not real-life one. Examples: procedural generation of plants, particle systems, movement along motion graph, etc. Often such applications are designed just to provide nice look and widely use random elements. But still in the simulation Physics and Dynamics can be used.
If planning of the next group of steps in your case of locomotion depends on game events and interaction with the scene objects, this is not “procedural-based” animation. If the actor or animals walk through the scene in random direction this is a kind of procedure generated animation. In any case algorithm of locomotion simulation still is based on Dynamics or Inverse Kinematics.