This is an updated design to my kinetic stand for the shark from LEGO set 31088 Deep Sea Creatures. This version of the stand has a much simpler design than the original, using less Technic pieces and more System parts. It also adds the opening and closing the Shark’s mouth, which really brings the shark to life.

You can see a demonstration of the model in the video below, and continue reading for the building instructions and design notes.

A full kit for this model is also available from BuildaMOC, if you want to conveniently get all the pieces needed to build it.


I was recently going through some older models, and realized my original base design for this shark was woefully out of date. The relatively recent release of gear plates, or ‘splat gears’, meant I could really simplify the mechanics used to achieve the swimming motion. I also thought it would be a good time to try and make the shark’s mouth open and close, which was a suggestion someone made back when I posted the original.

It turned out not to be too difficult, thanks again to some newly released pieces, though it’s definitely not any kind of standard connection. The lower jaw rests loosely on top of a transparent antenna, which is hinged at its base. As the head moves from side to side, the angle of the antenna changes, raising and lowering the top, and the jaw resting on it.

Instructions and Build Notes

Shark Modifications

In addition to the stand, several changes need to be made to the shark itself. This involves replacing all of the body joints, and the lower jaw hinge, so they all move freely. In the original model these are all stiff connections.

To accomplish this, you will follow a mix of custom building steps and steps from the original instruction manual. It should be pretty clearly indicated in the instructions which steps to follow and when.

Jaw Control

As noted above, the ‘connection’ of the jaw to the antenna is not a standard connection. The top of the antenna sits loosely in the underside of the round plate with bar attached to the bottom of the jaw. I have not had any issues with it falling out during normal operation, and either version of the antenna (flat top or rounded) should work.

Gear Orientation

The orientation of the plate gears, and the location of the turntables on top of them, are critical. These are very clearly indicated in the instructions, so be sure to pay special attention to them.

Parts List

The parts list only includes the parts needed to build the stand and modify the shark. You will need the parts from the original set as well to build the full model.