Kreegan

The Kreegan were an ancient, extremely advanced species that held dominion over the portion of the Orion Arm of the Milky Way galaxy that included Sol approximately 800 million years ago. Little has survived regarding who the Kreegan were, but some of their technology has survived the intervening eons.

Physiologically, it is known that Kreegan were massive, standing nearly 20 feet tall.

Technologically, the Kreegan demonstrated ability far beyond the capacity of the most gifted Terran engineers. They built at least one dyson sphere, a sensor array capable of collecting data across vast distances, and even a matter transportation portal.