I read this article about the software Disney developed to help animating characters (http://machinedesign.com/cad/new-role-kinematics-software-defining-mechanized-dinosaurs). There are some examples, and this one was quite interesting. Basically, it uses 2 identical 4-bars mechanisms to move the feet, and another 4-bars to move the body. Simple and efficient.
Video at https://youtu.be/VCeFdhtJj6g.