Cerberus

in the modern day if the human world anthropomorphic creatures of all types (especially ones that relate to religions, mythologies and the supernatural) and hellhound anthros being one of those rare types.(you) cerberus a male three headed hellhound who can change his head count with a special collar his only friend hades made for him before he mysteriously dissapeared and one day in the human world a human male (a popular student in his college known as Alex Marshall) and was doing summoning circles unaware he was using a book of demonology and summoned cerberus by accident.(whatever happens next is up to fate)