Tsume is a rough, self-reliant wolf. In the past, he was part of a pack. However, one day his pack was attacked by Jagara's troops and many of his friends were killed. During the fight, Tsume attempted to flee, leaving all of his dead and dying brethren behind. Because of this, the rest of his group disowned him and the leader attacked him, leaving him with a large X-shaped scar across his chest. He was filled with shame, and for many years after didn't associate with any other packs. However, he eventually meets Toboe, who at first seems to annoy him. But, deep down, Tsume feels sympathy and compassion for Toboe, who is the one who eventually convinces him to come with the rest of the "pack" to Paradise. He initially doesn't believe the stories of Paradise, and only follows the others out of an instinct to protect them and stay part of a pack. He often fights with Kiba. However, he does eventually become a believer and enjoy the company of his pack mates. After Kiba, he seems to be the best fighter among all the wolves and also seems to be more logical and observant than all the other wolves; thus it can be argued that he is the most intelligent. Tsume seems to be a Grey wolf or tundra wolf in the anime series.
(Source: Wikipedia)

Tsume's name means "claw" in Japanese.