My son recently got bought a Pincher Pals tiger and he loves playing with it. Maybe a little too much as the tiger's mouth eventually broke off at the main hub. I redesigned and printed a part to replace the hub half, making the walls extra chunky with my son in mind. This solved the problem for several months until the other side went in exactly the same way meaning that side also had to be redesigned and replaced.

With my modified hub it's now working great and currently no signs of wear.

Sketchup project file attached.