The Ninja Shadows were a phenomenon in Club Penguin, which appeared in several rooms. They could also be seen in the Dojo during the Halloween Party 2008. The Ninja Shadows appeared for a splitsecond during the Lightning Storm in the Halloween Party, and many players were often trying their best to capture a snapshot of the shadows. They seemed to appear when lightning struck and at the moment that the whole Dojo turned black.
- Its was secret in the Dojo during Halloween Party 2008.
- They returned for Card-Jitsu Party, appearing at the Dojo every few minutes ever since.
- When you dance while wearing the ninja suit, you actually disappear into a shadowy form instead of turning completely invisible.
- In November 2008, there used to be ninjas jumping from the sky and bouncing away. This one used to come every 5 minutes at the Town, HQ, Ski Hill, and the Plaza. After Card-Jitsu was released, these 'mysterious penguins' vanished. The ninjas found at the Lighthouse and Ski Lodge are still there.
- The ninja shadows have returned in the Dojo after the Card-Jitsu Party.