This is a food ball for a cat or dog. My cat is unsatisfied if he just eats food out of a bowl. He wants to hunt and play for it. In the past I have fed him with a dog treat ball, but this is laborious to fill, is breaking, gets lodged under furniture (it's small), and doesn't slow him down too much. So I made this! It takes him about 30 minutes to get all of the food out. It took about an hour the first day.

This design is customizable in OpenSCAD.
You should measure the size of your pet's food before printing this. My cat's food is 13 mm in the longest direction, so I made the holes 13.1 mm in diameter. The opening should be tuned to be large enough that the food doesn't get jammed, but small enough that it takes time to get the food out.
I feed my cat 1/4 cup (US) so I made half of the inner sphere be 1/4 cup. That way I can just scoop it into the food supply, lock it up, and give it to the kitty. You can adjust the food size for your pet in the SCAD file. Here be dragons: rendering this design takes a long time. The time is highly dependent on the number of facets, but that also dictates the quality of the render. This is my first design, so I am sure there are lots of performance optimizations I don't know about and the code is a mess. I recommend turning the number of facets per object down to <64 while experimenting with parameters.