Not much is known about the Star Gods, but sightings have been reported for nearly 500,000 years by Jogorians and even other races in the Viperius Galaxy. As the Star Book says, the Star Gods are a race of hyper-intelligent beings who created all life in the Viperius Galaxy. However, a catastrophic event millions of years ago led to the almost complete destruction of their race. As their race's superior reign came to an end by this event, they set out to create new life that would take their place when they left. And thus, the races of the galaxy were born. Centro is believed to be the old homeworld of the Star Gods, and much to the displeasment of the Jogorians, Centro has been colonized by many races, desecrating the ancient remains of the Star Gods. According to the Star Book, the Jogorians are the "Choosen Race" and are destined to become the next Star Gods before the current completely die out, leaving the galaxy vulnerable. Jogorians claim that the recent War Machine invasion is proof that time is running out for the Star Gods, and that the Jogorians must master immortality before it is too late.
All that is certainly known about the Star Gods is the fact that they have existed at some point in history and were very powerful, but then suddenly disappeared, whether or not they did create all life in the galaxy is open to debate.