In the Calvin & Hobbes collection Scientific Progress Goes Boink!, watch for the strip series where Calvin builds a duplicator, and duplicates himself. However, the duplicate makes 4 other duplicates before the machine breaks. Now, in the strip where all the duplicates are running from Calvin's mom, they all run past Calvin and Hobbes in the 3rd panel. Now, Calvin+ 5 duplicates= 6 Calvins. However, in this panel, in the upper right corner, there is a seventh Calvin, and he doesn't have a striped shirt, like the rest! Odd.