Sensei

The Sensei is a wise penguin who lives in the Dojo and instructs penguins on how to play Card-Jitsu. He can be found in the dojo anytime, but to get a background from him he has to be traveling Club Penguin, which only happens on special occasions. If you find him, click the box on his playercard for an autographed background.

What his player card looks like:

What he looks like in Club Penguin: