Cerbero

In Greek mythology, Cerberus also known as Can Cerberus, was the dog of Hades, a monster with three heads in the most common tradition with a snake in the tail place.
Cerberus guarded the door of Hades (the god of the Greek underworld) and ensured that the dead did not come out and that the living were not to enter. He was the son of Echidna and Typhon, and brother of Ortro. The existence of a hellish dog at the entrance of the infernos seems to be present in the original Indo-European mythology, since it appears in the myths of other Indo-European peoples, such as the blood-stained dog Garm in Scandinavian mythology.