Kerberos

Kerberos are magical beasts that were once Tod Hunds (Death Hounds) but were deemed too vicious to be used, thus they were sent to hell to become loyal to Satan and are tethered to either side of the gates of hell. These massive beasts were warped, twisted to become a demon who only desire to devour the people thrown at their feet. Hell Hounds have been starved and are switched out at the gates on a daily basis, only being fed once or twice a rotation.