This is a rolling stick toy (kururin). This rolling stick design is hollow in the middle and solid on the ends. This gives the effect of having weighted ends without adding anything to the 3D print. I printed mine with 100% fill to maximize the weighted end effect.
I used double stick tape to add foam end pads. The foam pads are made from craft foam sheet. I have also seen people use hot glue to make the pads on wood toys instead of using foam pads. Pocket83 has a good video on YouTube showing a hot glue technique (at the end of his wood kururin video)
I included the OpenSCAD file so people can download and modify the design if they see fit.
I posted a YouTube Video showing this design in action https://youtu.be/I6lPqif--r8