Cerberus

(地獄の番犬ケルベロスJigoku no Banken Keruberosu)

The terrible watchdog from Hell. He appears in vol.23 of Kurumada's manga, devouring souls in the second prison of the Underworld. The Specter, Sphinx Pharaoh, was fond of the creature and took care of him. Kerberos was defeated, although not killed, by Pegasus Seiya and Andromeda Shun, to be able to proceed further into the Underworld.