How To Become A Shadow Ninja
Card-Jitsu Shadow is a possible future game in Club Penguin. Throughout the Card-Jitsu series, there have been numerous hints about its existence. Like: On his Twitter account, Spike Hike got a tweet asking if there would be a Card Jitsu Shadow. He replied, “Snow first”, which likely proves that Card-Jitsu Shadow is coming out. When also asked whether it is real, he said it is a rumor but he believes in it.
On a Club Penguin Memories post of Ask Spike Hike, Spike Hike mentioned that there would be something big for Card-Jitsu. He may have been referring to Card-Jitsu Shadow. He also mentioned something big for Puffles (possibly Puffle Party 2014 or Puffle Wild).