The Illustration Friday theme this week is Zoo, but I kept thinking about the new Leopard operating system on my Mac. Then I remembered that all the previous Mac OS X operating systems were named for big cats, and I thought the big cats might have to go to school to learn the difference between a mouse and mouse. So this is my Zoo School for Big Cats. (click on it for a bigger version).The big cats in class from left to right are: Leopard, Cheetah, Tiger, Puma, and Jaguar. Now it probably makes sense why I was drawing big cats in my last post.