You cant be a ninja on CP. Not yet. Penguins have told me how to be a ninja by going to the dojo without moving for 30 minuets and other stuff like that. Trust me, ive tried. But if you go to www.clubpenguin.com and click on the "N" in night club above the blue penguin, the blue penguin turns into a ninja penguin! From my research, right now, you cant become a ninja.