Boxes constructed by stacking layers so as to make ribbed surfaces. One set of boxes is shaped like a dolphin, a second set like a shark. Based on two of MaakMijnldee's cookie cutters. http://www.thingiverse.com/thing:35495 - OpenSCAD code is included.
The boxes, as output by my printer, have tight fitting, "snap on" lids. The lids can be removed by carefully pushing up on an edge.
Details on how to construct input files from the cookie cutters are given in the openSCAD code. Any of the over 100 MaakMijnldee cookie cutters can be easily converted to a decorative ribbed box.