Hōzuki Castle's Ninken

This dog is the personal summon of the current prison master of Hōzuki Castle.

Personality
The guard dog is very obedient to whomever is official sanctioned as the prison master.

Appearance
It is a massive dog with brown fur and yellow eyes, it has two independently acting heads.

Abilities
Belying its massive size, it is very fast and agile. It is also able to produce powerful flames from its mouths. It is also very strong and resilient, able to plow through rock and endure most enemy attacks. As with most dogs, it has a powerful sense of smell, able to track down it target by catching their scent.

Mujina Bandits Arc
When Benga learned of an escape attempt by Team 7 and Kokuri, using his newfound position as prison master, he summoned the Two-Headed Dog and hunted down the escapees. The dog quickly proved a dangerous foe. Sarada Uchiha however took advantage of the build-up in water from the rain in the underground caves, breaking down the walls to make the water rush in and rush the dog away, forcing it to disperse.

Trivia

 * This summoning is seemingly a reference to the Cerberus, the multi-headed guard dog of Hades.

  

Nin-Ken