An ancient race of bird-like humanoids once populated several planets across the galaxy. They were brilliant scholars, incredible warriors, and peaceful above all else. Their pursuit of knowledge led to technological advancements beyond anything in the galaxy today. One of their most significant discoveries was a small, desolate planet labeled SR388, which held a secret: a peculiar parasitic creature called a Metroid.
The Chozo were fascinated, studying the Metroids’ energy-sapping abilities and seemingly invulnerable hides. The endless amounts of energy these creatures produced offered incredible scientific possibilities. It wasn’t long before the Chozo were harnessing these capabilities, and soon after, SR388 became a flourishing colony.
However, the Chozo were unprepared for the dangers presented by maturing Metroids. The creatures morphed from one stage to the next and multiplied so quickly that all attempts to control them soon collapsed. The Chozo’s ambitions rapidly shifted to a struggle for survival.
The Chozo came to an understanding that the Metroids weren’t only a threat to the planet, but, in the wrong hands, a potential threat to the entire galaxy. They devised a plan not only to stop the Metroids, but to prevent anyone from using them to their own ends. They flooded sections of the planet with a purple liquid that put native wildlife into stasis, and severely burned any non-native life. The Chozo then placed seals in each major region of SR388’s interior. Unlocking a region’s seal and draining the purple liquid would require the destruction of every Metroid in that region. So, to venture to the next region, working deeper into the planet, an intruder must destroy every Metroid in the region before. Splitting up the Metroid population this way was the only plan the Chozo could pull off without falling prey to the Metroids themselves.
The events that followed are lost to time. Theories of the Metroids escaping and destroying the Chozo, and murmurs of infighting between the once-peaceful species, can be found throughout history books, but this is little more than speculation. No one knows what became of this brilliant race—not even the small pockets of Chozo still living today.