Hell Cerberus is the Rank Up (Evolution) of an Orthrus after it reaches Lv100.

Rou's mount and pet, the Black Wolf Leader Kurosaburou ranks up into Orthrus, which then ranks up into Hell Cerberus.

He has a third head. With bristles as black as darkness, his shoulders stand at about 4 meters.
Near the neck grows countless snake heads spitting fire and poison.
The tail looks like a dragon's tail. With the number of heads, large body, snakes on his neck, and serpent-like tail, he might look a little scary.
The black bristles are soft and fluffy, and feel very good.