Cerberus is featured in several mythological stories in his role as the watchdog of Hades. Perhaps the best known involves the vigorous hero Herakles (or Hercules, if you prefer the more familiar Latinized version). Herakles underwent a series of Twelve Labors, one of which was to capture the fierce canine guardian and parade him around the Greek city of Mycenae for a bit, and then return the dog to Hades. This unbelievable stunt was in due course accomplished by the hero, although one would imagine that Cerberus did not enjoy it in the least.
Another tale depicts the poet and singer Orpheus charming Cerberus by the power of his song, which emphasizes Orpheus's magical gifts of enchantment (indeed, Cerberus was notorious for not allowing mortals who were still alive to enter the Underworld, with the exception of a handful of mythological characters).
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Who's Who in Classical Mythology
This book is a great source for information about Greek and Roman mythology! There are good entries on many Greek creatures.
This book is a great source for information about Greek and Roman mythology! Organized alphabetically, this who's who features information about over 1200 of the most intriguing characters - and creatures - from Classical myth and legend.