Soft Bodies experiment
For this one, I chose to experiment with using soft body dynamics on his hair so that the secondary action would animated automatically and correctly. At first, I just made the hair itself a soft body and set evey vertex on the hair to have a goal weight of 1 except for the vertices I wanted to move (namely the front of the hair and the little hair sticking out of the top). While this worked immediately, I wasn't completely satisfied with the results. The hair would move and bounce, but it wouldn't "flow" if that makes sense. It looked like the parts would move as a solid mass. So instead of making the hair itself a soft body, I made joints for the parts of the hair I wanted to move and smooth binded it to the hair. I painted the weights for the joints so they could control the vertices I wanted them to control. I then integrated the joints I created with the original joint system of the character so they could move along with the rest of the rig. Then, I made spline IK's for each of the new joint chains I made and made the spline curve itself a soft body (duplicate, make original soft) and made the duplicate a goal. Then, I selected the particles that were made along the spline curve and lowered the goal weighting of each of them a little more as the particles got further from the head so that it could move similarly to a tail. Once I played the animation I made, the hair worked almost exactly how I wanted to. I just had to mess with the goal weighting until it moved enough, but not too much. I also did the effects on the Jell-o at the end and the particles in the beginning.