Okami Easter Eggs
Loading Screens
One of the loading screens is a trail of paw prints - you can make the prints bigger by pressing X before they appear. On a longer load, do this all the way through the loading, and rather than seeing Issun, you'll see demon fangs.
On the other loading screen pressing X places prints on the screen. Press X rapidly enough and you'll see the demon fangs.
If you get the demon fangs in either loading screen, demon fangs will appear in your inventory.