Coffin for D&D, 2"x1". The lid will snap shut as long as your filament size is properly specified. Printed on a Replicator. Since it's hollow, you can put items, gold, or enemies in it for your PCs to find. On the last photo, you can see me holding it upside down with the lid staying in place.
I printed it with my orignal filament with the original diameter size of 1.82 and it worked perfectly. Once I got new filament, the lids stopped fitting. I measured my filament and the new stuff was 1.75, so I changed my settings, regenerated the g-code, and it started fitting again.