This is a little toy I made for my grandson before Christmas. The pieces were really simple to make -- cut, layer with batting, stitch, and turn. Add a buttonhole near the center and stitch buttons onto a ribbon. The square is about 3", the rest are nearly that size.
At 18 months I think Mali's old enough to learn to button (with very securely attached buttons!) and learn colors, and it won't be long until he can learn shapes, too. Will he like it? We'll have to wait for a few more days because we didn't spend Christmas together.