never heard of cerberus?
the gateguard of hell
the 3 headed hellhound
edit:
cerberus
The three headed dog from Greek mythology, was the offspring of Echinda and Typhon. It is the brother of Orthus. Cerberus acts as the guard of Hades. It is said to have a serpent for a tail. Some say that the Cerberus, instead of having three heads has fifty. It was one of Heracles' tasks to take the Cerberus out of Hades, which he succeeded in doing. The only other person to foil the Cerberus was Orpheus, who charmed the beast to sleep using his lyre.
http://webhome.idirect.com/~donlong/monsters/IMAGES/Cerberus.gif