Mountain Bison is a Hokkaido Wolf. He is mainly white but has black stripes on his face. His back and ears are also black. He has fluffy cheeks and a scruffy hairtuft on his forehead. In Meteor Gin, he is described as looking unusual for a wolf.
Mountain Bison was trained by Juga to be a hakkenshi of Sirius. Just like the other hakkenshi of Gaia, he believed he was a true hakkenshi. He awaits Gin's groups arrival with Black Snake. He never fights and his technique isn't seen because Juga interrupts the fight between the two groups before it's his turn. When he tries to stop Gin from following Juga, he is knocked aside and eventually defeated by Raiga, Sakon and Ukon. He is not seen again after this and likely died during the earthquake which destroyed the Underworld.