This is a rather complex model. The base of the model is a simple box with hinge. The base box can be downloaded from here. The cover, eyes and teeth are attached around it.

The tricky part is in the modelling to make it printable. The tentacles on the cover needs support which should be removed after printing.

The upper part is sliced into to two parts to make the printing easier. One part is the top part with eyes. The other part has the hinge and the tentacles with support. These parts are glued together after printing.

If you don't have a printer, you can buy it here.