Ninken

are any dogs that have a decent chakra supply, and thus are able to work with ninja. Some, such as Pakkun and Kuromaru, can talk. Although the dogs belonging to the members of the Inuzuka clan are ninken, the phrase is usually used in reference to the pack of eight ninken summoned by Kakashi Hatake. Kakashi's ninken have shown the ability to walk on water.

Kakashi summons his ninken mostly for tracking purposes. He can summon them separately, as he commonly does so with Pakkun, or all together. He can also summon them for special purposes, like he does with his Summoning Technique: Earth Release: Tracking Fang Technique. With this technique, the dogs can travel through the ground following the scent of their target, emerging when the target is found and holding them in place. They all have a face-shaped design on their backs called, which is the sound made when all the characters in the face are put together. Appropriately enough, children use this design as the face for their scarecrows, which is Kakashi in Japanese

Inuzuka ninken

 * Akamaru
 * Kuromaru
 * The Haimaru Sankyodai

Others

 * Giant Multi-Headed Dog (summoned by Pain's Animal Path)