Kuromaru

Kuromaru is a grown, wolf-like dog whose coat is black on top and white beneath, closest in look to the Northern Rocky Mountain Wolf. His left ear is gone, and a patch covers the right eye. By Part II he has bulked up considerably compared with the brief glimpse of him in Part I.

Kuromaru stands out among the Inuzuka hounds as the single ninken known to speak in human words. Fiercely devoted to Tsume, he acts less as a pet than as her equal on the battlefield, coordinating with her as a true partner rather than a mere animal.

In battle Kuromaru fights hand in glove with Tsume, launching the Inuzuka's paired attacks and handling clan arts, the Fang Passing Fang among them, which he wields well enough to tear deep into the corpse serving as Pain's initial Animal Path. During the Konoha Crush he and Tsume stand with the village's defenders, joined by the Three Haimaru Brothers and Hana Inuzuka, driving back the invading Otogakure and Sunagakure forces.

When Pain later assaults the village, the pair corner the Preta Path in a morgue as it moves to discard the old Animal Path, tossing in a canned flash bomb, then striking with Fang Passing Fang. The enemy hides behind the earlier corpse and clings to the ceiling, so Tsume climbs onto Kuromaru to give chase, with Kiba and Akamaru soon joining in. Akamaru marks the target, but it is summoned away before Pain levels the village. Kuromaru comes through unhurt and is later seen celebrating Naruto's win over Pain.