The Ninja Mask is the only part of the Ninja Suit you have to manually put on and if worn, you transform into the Ninja. Only the chosen Ninja could wear it, as the person must have the heart of a ninja. When Randy puts it on the red lines glow and entangle him, forming the ninja suit. The Ninja Suit was woven from a Tengu's feathers. The mask can reform itself after being destroyed as in "Evil Spirit Week" it reforms from five creatures can be seen (nine in the storyboard): the tengu, a carp, the twin baku, and a wani (dragon) and made more Tengu feathers. The mask is made portable and can be hidden easily.
If the Ninja abuses his powers, the mask will not turn into the suit when he puts it on until he unabuses them. This happened in "Swampy Seconds" when Randy abuses it to cut a hole in the fence. He unabuses his ninja powers after escaping one of Catfish's cages without the suit and sacrificing himself to save Howard from getting mauled by a panther.
- Knowing the Ninja suit has a different design for each Ninja, it's unknown if the Ninja mask changes appearances as well.
- The Ninja is usually the only person who uses the mask, but people who aren't the Ninja can also use it, like Howard in "The Ninja Supremacy".
- The mask and the Tengu are linked. If Tengu possesses someone, the Ninja can choose to burn the mask, which releases the person from the Tengu's control and sends the demon back into the Eye of Eternities.
- When Randy does this for the first time to free Howard, he receives a ninja skill called Ninja Rage. It appears that it's a new ability for the Ninja, as no other ninjas seem to be able to do it.