Rentwhistle Swack is a con man who was previously arrested by Booster. He was first seen poaching creatures on Karn where he also bagged Booster in his hunt. He had some of the creatures that he poached brought to a space station where he met up with some hunters that started poaching Booster. While the hunters were hunting Booster, Rentwhistle Swack fled the area only to be intercepted by Team Lightyear and Dr. Ozma Furbanna. The hunters were defeated and they alongside Rentwhistle Swack were sentenced to community service on Karn by Booster. Rentwhistler Swack was later Norbert Q. Klerm's "agent/booker/tour guide" when Norbert was making Buzz and Emperor Zurg fight each other.