This is a flexible, multi-segment horned starfish. You can customize the number of legs, number of leg segments, and the length of the leg segments, providing considerable aquatic diversity. This stylised design was inspired by the horned starfish that inhabit the waters off the coast where I live. My kids have rescued many of these starfish when they become stranded during spring tides.
You can download and build the entire project automagically using make. However you will need to comment out the starfish(part); line in the OpenSCAD source file in order for make to work properly.
If you are doing a print-in-place, you may want to increase the gap so the parts don't stick together. If you are printing them as separate pieces, then 0.0-0.1mm provides a nice tight fit.