Breed: Three-Headed Dog
Original Appearances: Greek Mythology
Other Appearances: Cerberus has also appeared in many forms of popular media, from other mythology to comic books to movies.
Biography: Cerberus (a Latinised version of the Greek Kerberos) was the sibling of the Hydra, the Nemean Lion, the Spinx, the Ladon, and the Chimera. He was the offspring of Echidna, the half-woman/half-serpent, and Typhon, a fire-breathing giant. His brother Orthrus was a two-headed hellhound. Most depictions of Cerberus show him as having three heads (one head seeing the past, one the present, and one the future – or else representing birth, youth, and old age), and occasionally a mane of live serpents (similar to Medusa). Cerberus only eats live meat, and so allows the spirits of the dead to freely enter the underworld, but allowed none to leave. He served as Hades' watchdog. Heracles' last of his 12 labors was to capture Cerberus alive, without using weapons. He accomplished this by getting first getting Hades' permission to bring Cerberus to the surface world, and then overpowering Cerberus. In another myth, Cerberus was lulled to sleep with music by Orpheus.
Powers: As noted above, one interpretation of Cerberus' three heads was that one could see the past, one could see the present, and one could see the future. Cerberus was apparently also very strong and nearly invulnerable.
Group Affiliation: None
Miscellaneous: Fluffy, the three-headed dog that guards the Philosopher's Stone in “Harry Potter and the Philospher's Stone” (renamed “Harry Potter and the Sorcerer's Stone”) was based on Cerberus. Also, I have no idea why a certain Aardvark got the name.