Rocket Raccoon
Centuries ago, a group of alien humanoids settled the largest planet in the Keystone Quadrant star system. They built a complex to house and treat the insane, recording their medical observations in a psychiatric diary. When their funding was cut, they abandoned the project, but not before they created a staff of robots to provide for the humanoids. They then separated the quadrant from the rest of the galaxy with an impenetrable force field.
When a nearby star went nova, ensuing radiation gave sentience to the robots, who quickly chafed at the illogical of the humanoids, or "Loonies." Seeking to end their servitude, the robots used genetic engineering to give intelligence and awareness to the animals that had been left as companions for the patients. They charged the animals with the patients' care and protection, then relocated to the far side of the planet, which they proceeded to strip bare through industrial endeavors, one of which was construction of a vast, humanoid spacecraft called Ship. The half-industrial, half-verdant planet became known as "Halfworld." Rocket Raccoon acts as the "Guardian of the Keystone Quadrant", an area of outer space sealed off from the rest of the cosmos by the so-called Galacian Wall and was Halfworld's chief law officer ("ranger") who protected the colony against various threats.