The Coreeshi were an alien species.
Little was known about the actual appearance of Coreeshi because they grafted themselves into bipedal bioengineered exoskeletons. What was removed from the exoskeleton was an orange goo. They possessed the technology to shrink objects and creatures with a reduction beam, housing captives in capsules which could be inserted into the exoskeleton. The Peacekeepers used Coreeshi bounty hunters in their search for Moya's crew. These bounty hunters had exoskeletons that acted as body armor, able to withstand pulse blasts. ("I Shrink, Therefore I Am")