Rolly polly, tumbler for dog

This is my attempt at making an interactive feeding dog toy in the form of a roly polly, tumbler, or wobbler. I made two types one for small dogs, like chihuahuas or less than 10lb-dogs and another one for dogs in the 20lbs range. The design is not perfect but it does wobble and keeps them interested while there is tasty kibble or treats inside. The small version should be able to hold 1/8 cup of small kibble and the bigger version at least 1/2 cup of kibble.

The one for small dogs has a base