Snap-together rolling ball with semi-round smaller ball inside so it doesn't roll straight. No glue needed. My cats love them! I also cut off small bells from broken cat toys and add them inside to make new cat toys.
The ball is printed in two halves with the round-side up with paint-on support only needed on the bottom of the male side; the female side requires no support. Print the small ball as well with one of the flat sides down, then put the small ball in the two shells and they will snap together. Then roll it for your cat!
Video of my cat Simon playing with one: https://youtube.com/shorts/kbKCVy5hH7k?feature=share
The author marked this model as their own original creation.