Two Easter Eggs are listed below.
Clouds pass by on the Ninja Warz application homepage. Clicking on them will cause them to disappear, Occasionally, gold-colored clouds will float by, which yield Gold when clicked. The amount of gold is determined by level, but varies slightly. (An even rarer occurrence- two Gold clouds will appear on the screen at once; one will have a reward and the other will be empty, showing an error message instead of the Gold gained message.)
Another Easter Egg on the homepage involves birds that fly by on the screen. When clicked on, they defecate. After clicking repeatedly on the bird for a while, it will begin to spew its fecal matter automatically. After reloading the home screen, the droppings will dissappear.