Sith hound was four-legged aggressive creature that was trained and used as war beast by Sith Empire on many planets - including Balmorra

Balmorra Planet

and Corellia

Corellia Planet

- during and after Cold War

The Cold War Event Cold War (3653BBY - 3642BBY)

. The name of the beast was pure conjecture - it had "Sith" in its name, because the beast was often seen in the company of Sith warriors - different sources called it differently - including such names as bonegnawers or even kath hounds. Some have even speculated that the Sith Hound was actually a mutated tuk'ata beast - evolutionary or with the help of Sith alchemy, which itself was a rare sight outside of the planet Korriban

Korriban Planet

and very little was known about it.
They were very similar in appearance to Balmorran Greatmaw hounds

Greatmaw Hound Creature Non-sentient

and were possibly related to them - the only significant difference between the two was that the two bony tusks that protruded from their jaws were much smaller than that of the Greatmaws. During the Imperial occupation of Balmorra, Sith beastmasters

Sith Beastmaster (Sith Order) Organization Reconstituted Sith Empire

were tasked with a training of the already ferocious hounds. Beastmasters proved to be successful - many Sith Army

Imperial Army (Sith Empire) Organization Reconstituted Sith Empire

patrols in the Southern Markaran Wastes were accompanied by the trained hounds, guarding the approach to the Imperial Command Compound.