Cerberus.
The monster that guards the exit from the Underworld is Cerberus (Kerberos).
None: Persephone was a goddess of the Underworld, where monsters dwell, not a goddess of killing monsters.
Cerberus was a mythological creature. a Dog like monster with three heads whom lived in the underworld.
He could see ghosts, and evidently kept them within the Underworld.
The minotaur sent Percy's mother to the Underworld.
The fiery Dragon is Hades God of Underworld or the seven headed monster is Hydra
Difficult to answer - he is the servant of Hades - in the same way that Cerberus is Hades' pet dog. As a resident of the underworld he is not a mortal but he is also not a god. However unlike Cerberus he is not a monster.
Perseus only loved and married a woman named Andromeda. He won the right to marry her after he slew the sea monster and freed her from where she was chained - she was to be an offering to a sea monster, sent by Poseidon
All the creatures of the Underworld, originally. Now you can be anything for Halloween - a monster, a celebrity...Even a video game character.
Any stories involving the Underworld. Cerberus was the three-headed guardian of the entrance to Hades.
The Batman Superman Hour - 1968 Partners in Peril The Underworld Underground Caper The Ghost of Kilbane Castle The Monster Molecule 1-7 was released on: USA: 26 October 1968