I call this shark "Mk II" because it is the second generation of moving sharks that I've built so far. The first one was built out of set 9394 6 years ago. New shark features two motorized functions: moving tail and opening maw to eat moving fish. You can turn them on separately or together with help of two red levers on stand. You can watch it in motion in this video. Building instructions can be bought exclusively from rebrickable.com where you will be redirected after clicking on "Download instructions".