Ninji
A Ninji is a black, blue, or purple, star-shaped ninja creature that first appeared in Super Mario Bros. 2. There are two types of Ninji: the first type charges at Mario, suddenly jumping as they approach; the second type remains in one place and jumps up and down.
The Ninji also appear in Super Mario World. They make their appearance in only one level, the final level, in fact. These Ninji are black, making them difficult to see in the darkness of Bowser's Castle (unless the searchlight is turned on). Strangely, the Ninji appear in 8-bits, even though the game is in 16-bits.
Ninjis in Hotel Mario were called Mini-Ninjis, but there is no difference between regular ones and minis.
In Paper Mario, the Ninji act as the protectors of the Star Kids in Starborn Valley and are friendly, non-enemy characters.
In other media
In the Super Mario Bros. Super Show episode "Karate Koopa", the Ninjis helped King Koopa attempt to defeat Mario and the gang. In the show, they were called Blackbelt Ninjis (since they wore black clothes).
