Creature:Karnite

The Karnites were an empire with the scientist archetype who studied methods of alternative energy. They lived for billions of years before destroying their empire with their own knowledge

Anatomy
The Karnites were bipedal, jawless creatures with four-fingered hands. They evolved to become bipedal as creatures and could see more of their world, giving rise to their passion for science as an empire. Their ears were shaped like tubes and hang from their faces onto their chests so they can hear their heartbeat, because they couldn't control their heart rate and had to prevent it from getting too fast or too slow. Their brains had more overall area than that of a human's or most of the other Empires, meaning they could store more memories and solve problems quicker.

The "accident"
The Karnite Empire spanned several systems and all the cities and colonies were run by the same method of energy, which was controlled by a center computer. They didn't know, however that the energy had a flaw, and the center computer crashed. This error caused the energy outlets to explode on all the cities and colonies, making the Karnites extinct. The only race to have ever interacted with the empire have referred to it as the "accident" from then on.