These are variations of ball made with modular origami units, each of which is made of square paper.
This model represents quasi-regular polyhedra, which consists of regular triangle, tetragon, and pentagon.
Tetragon is easily found on the face of this model. Triangle and pentagon are represented by the base (actually you cannot see the base) of polyhedron set.
These are unique variations of unit origami. They look like having belt around them.
There are variations in the shape of balls made with this type of units as well as balls made with normal unit origami.
The koala doll is a souvenir from my friend who made a trip to Australia.