Name: Jack
Japanese name: ジャツク
Sex: Male
Breed: Unknown

Jack is a hunting dog and owned by Ninomiya. He lives together with Joe, Bomb and Guilder. One day in the forest, Jack meets Joe's brother Weed along with the rest of his pack mates. Together they scare of a bear threatening to kill them.

Later, Jack and his pack mates are out to find a bear that has attacked a human. As they climb a rocky ledge of a mountain, they are bombarded with rocks. The bear is waiting on top of a cliff, pushing rocks down at them.
His leader, Joe, is seriously wounded by the bear.

As Jack enters a fight with the Hybrid bear, he gets crushed as te bear smashes it's paws down on him.