Read about my design ideas below.
Last night I started work on the dragons head. I had a flash of inspiration during the day and scribbled down this sketch which I used as a plan.
Then I built the head out of cardboard, bamboo stick, marionette string, gaffa tape, a piece of wire and, of course, all stuck together with hot glue. My idea with the piece of wire was to allow more movement of the head in a side to side direction buy with the neck anchored at the bottom with the gaffa tape. This was a bit unwieldy so I ended up just added the gaffa tape all the way up so its just a basic hinge movement.
The spring and the mouth opening works quite well. I've uploaded a video on youtube showing the movement of the head. Click the button below to go to youtube.