WOW
I love that jaw mech! I've made a similar wooden model. I don't have a camera but I've drawn a design of it.
Photo
I like the ring under your mouth lever. I may put a ring under my trigger too. I rest my thumb on the back peice to move it side to side or up and down and the makes the head move too. Here's the up and down head movement animated gif.
PHOTO
I havent put any material on it but it moves really well.
yes I'm proud of my design too lol