Halfworlders are a race of artificially-engineered, bipedal, anthropomorphic animals created on Halfworld, a planet-sized insane asylum in the Keystone Quadrant. The facility was originally overseen by Robot Stewards created by an unnamed humanoid species who left the planet in their care until radiation from a nearby exploding star caused them to gain self-awareness. Before abandoning their post and migrating to the other side of the planet, the robots sent probes across the universe to gather creatures which they would genetically modify to act as their replacements. Representing a number of animal species native to Earth, their cute appearance was specifically selected to make them more pleasant caretakers for their mentally unstable patients. The Halfworlders maintained order on their planet by acting as attendants and security guards while distributing toys to keep up patient morale, which later became a booming enterprise. While bad denizens such as the lizard Lord Dyvyne and mole Judson Jakes tried to turn this industry into one of war, Rocket Racoon and his friends were able to both defeat them and create a "wonder toy" that cured all the "loonies" of their insanity before heading into space to seek new adventures.
However, it was later revealed that Rocket's recollection of his days on Halfworld were only half true; implanted memories that he gave to himself to protect the planet from an even more devious threat. Unlike the original story, Halfworld was not in fact a verdant paradise of merry critters and "loonies", but a cold, sterile facility where the insane were strapped to chairs and sedated. One such patient was Star-Thief, an incorporeal lunatic possessing the body of a committed man, who used his possession abilities to turn everyone into bloodthirsty killers. Eventually, Rocket was able to trap Star-Thief's body in the deepest recessed of the complex, which required all animal guards present to open. He then wiped his own mind and left the planet as to remove all temptation of returning, and insuring his captive would remain isolated forever. By happenstance, he would return sometime later and learn the truth, this time permanently defeating Star-Thief by trapping him in a virtual prison.
Some Halfworlders, such as Blackjack O'Hare, would become mercenaries in their own right. Others galactic wanders searching for or attempting to avoid their unpleasant past.
- 73 representatives of Halfworlders
- 397 appearance(s) of Halfworlders
- 46 minor appearance(s) of Halfworlders
- 3 mention(s) of Halfworlders