Downloaded and printed the following track ball cat toy:
https://www.printables.com/model/106696-track-ball-cat-toy
The tack ball cat toy required ping pong balls. Instead of buying ping pong balls decided to 3D model one and print it. The ball is printed in 2 pieces which you would have to glue them together. The outside diameter of the ball is exactly the same size as an original ping pong ball.
Made 2 different variations. One with a hole on the end. The hole is big enough to put a treat in to keep the cat busy. The other design is with hex grid, because I think it looks cool.
The pieces can be printed without supports, however, It prints better with supports. I have uploaded a 3mf file which has organic supports already set. I did this on PrusaSlicer. I don't know if organic supports will works on different slicers.
Enjoy
The author marked this model as their own original creation.