Here are the rigging stages I went through to get my Hookworm moving. There are a few more tweaks that need to be made but that will come once all of my other models are ready to go. These images are from my second attempt at rigging as the first attempt went badly wrong. Remember to merge different models together before attempting rigging, otherwise you get an active body and one lazy head.
I started by plotting out the Joints as you normally do and then joined a CV curve onto them as a foundation for the later movements.
Cluster's were used to make it easier to grab hold of the Curve's vertices and then nurbs circle's were used for the main controls.
An example of how the rig moves.
Final shots of the Model and its controls, how the worm moves and a video showing the Model moving in a unrealistic way just to show how it moves.