Cerberos

Today we will have a closer look on a creature and later you can decide if the creature is part of the Greek mythology or an invention of Hollywood.
Basically, the monster I am going to talk about, is a dog called Cerberos.
But of course the Cerberos is not a usual dog as you or your neighbours maybe have at home.

Instead he is depicted by not only one but three heads and its tail as well as its back insist of living snakes.
The dog originally belongs to hell because there its main-duty is denying dead people the escape out of hell.
Furthermore it hinders alive people to enter hell too.
One simple breath is deadly which makes him the perfect guardian of hell.
Only a handful of characters were successfully able to past this beast.
But even a crucial and deadly creature as the Cerberos is has its weaknesses.
Neither can it resist the sweet taste of honey-cake nor is it immune to good music potentially making it fall asleep.
In general the Cerberos avoids the world of mortals, so there is no danger for people who are alive.
But in case that it is there, its spittle lets grow the toxic flower Akόniton when it falls down to the ground.

So now it is your turn:
Do you think, that the Cerberos is part of the Greek mythology or are you sure that it is just an invention of Hollywood?