I would suggest something mythological.
Cerberus - the three-headed dog who guarded the gates of Hades' realm
Carcharoth - (Tolkien equivalent to Cerberus) a great wolf who guarded the gates of Angbad
Huan - the elf-hound who killed Carcharoth
Csodaszarvas - the "Miraculous Deer" from Hungarian myth who led two brothers to the land where they founded the Huns and Magyar tribes, also the name given to one of planet Reach's moons in the Halo universe.
Asha - the Amesha Spenta (basically the Zoroastrian version of greater Angels) of Truth