Ninneko

are able to work with ninja due to their keen senses and unusual flexibility. Many live in Sora-ku with Nekobaa and Tamaki; in Konoha Hiden, ninneko are responsible for providing security to the city's various black marketeers, observing those who visit the city and, if they mean ill, causing them to become lost.

In the anime, ninneko live in a castle and do not possess affiliation with any country or shinobi villages, though a few have been shown to wear a forehead protector with the kanji for written across it. They protect and roam the corridors of the Fortress and intercept any threats.

Abilities
In Konoha Hiden, ninneko are stated to remove their scent during their standard grooming in order to allow them to move around undetected. Momo displays the ability to use his fleas as projectiles and his food as a clone.

In the anime, ninneko primarily use taijutsu since their flexible muscles grant them great speed. Their claws act as natural weapons, which they can flow chakra into to make them sharper. Nekomata has demonstrated the ability to cast genjutsu.

Bakeneko
are large cats who have a split tail, giving the appearance of two. They are significantly larger and stronger then the average cat. How the transformation from cat to Bakeneko occurs is unknown.

Known Ninneko

 * Denka
 * Hina
 * Momo (Konoha Hiden)
 * Nekomata (Bakeneko) (anime only)
 * Matatabi (Bakeneko) (anime only)

Trivia

 * In Naruto: Shippūden episode 189, Sakura Haruno observed that a ninneko may be defeated by throwing water over it because of its fear of getting soaked.