This design is based on a clear acrylic toy I had as a kid that when put together, looked like 4 ice cubes. I haven't gotten into printing transparent filaments yet, but this is on my list of things to make when I do.

The cubes fit together with a hollow space between so you can hide things inside each one for a surprise to whoever opens it up next.

Supports will be necessary and I may try to iterate to make it easier to print, but I wanted to keep it as close to what I remembered as a child.